Scrape or sand or https://www.wagnerspraytech.com/products/surface-prep-tools/paint-eater/

Feel grain?

1. Random orbit sander from 80 to 120 to higher grit until it's Smooth to the touch.

2. Most of the time on bare wood, primer first. Improves binding and hiding of the grain.

3. Paint.

But if you want to do gravel....

https://unilock.com/storage/2019/11/advanced-tech-guide-en-final-lr.pdf

That's a good reference on what you'll need underneath and to the sides...

But as for the edge, you can do anything from metal to wood to bricks standing on edge embedded flush into the ground to keep the edge straight and from moving about.

Really depends on just how "muddy" and quick that ground becomes...

https://www.familyhandyman.com/project/this-paver-patio-base-will-save-your-back/

Look at the photo between plastic paver vs traditional base - the point is you don't need gravel!

Depends on how much maintenance you want.

Similar side walkway here, but dropped in concrete pavers decades ago and never need to deal with mud, grass, etc. Just a clean walkway front to back.

Naturally, you'll install with a slope away from the home, and towards the front of the home so rain naturally flows towards, then under that fence door then to the curb. Against the side fence, you'll want to slope away from that, too, so the water doesn't run into the neighbors. So looking at the walkway - a slight "v" shape for the slopes.

Naturally, if the neighbor's land is sloped such that it'll dump rain at their side of the fence, you might still get too much water on your side (rain from both sides pooling on your walkway).

If they don't slope and drain properly, only way is to replace that wood fence with a concrete block wall that'll keep their water on their side. (And then instead of a wood fence lasting a decade to a few, a concrete wall that'll last many decades.)

If you have tons of rain, any drain system can help if it tends to pool in one place despite proper sloping. For extremely rainy areas, you might even need underground catch basins. And modify the gutter drain to dump water on the other aside of the fence door, ideally many feet away from the foundation, too.

Also, used to be you needed tons of digging and sand and base, but with plastic paver bases and weed liners, much quicker and easier to get a nice base for the pavers.

Pipe cleaners or anything else like a toothbrush for kids + vacuum cleaner hose next to that to suck up loose dust.

And as a person who's seen crazy things from actual life, you'd know that what should be a perpendicular stud might actually be installed "wrong" because people are sometimes idiots and then you get buildings with all sorts of WTH!?!...

There's no info from the op whether that wall was there originally, or someone moved/turned a wall and built a new one around whatever studs were there. No info on the actual architecture of the home, etc.

....

So, rather than assume from afar, which is one way to make the unexpected into a real problem, simply proceed as if that is a true load bearing stud to minimize the Oh F#!*' moments.

This is also safer for the op because he doesn't have any good way to ensure 100% whether this is or isn't load bearing - doesn't have the access or experience.

No. Engineer.

But everyone skilled in the trades or not can learn the basics of structural integrity and such.

Even lego structures teach a lot about what can be removed and what will bring the house down.

I mean... Even 2x4 studs 16 to 24 inches apart for a wall - what can take one down? In Real life?

You'd have to drive a car through the wall, fire, or major earthquake for the wall to truly "fail" in a bad way.

Thankfully, lawyers and architects understand they need to design around dummies, resulting in construction code that builders follow to build structures capable to withstanding stresses well beyond what stresses the majority of buildings actually encounter in their lifetimes.

But code isn't the only way to build a strong home.

E.g. Go to an Pacific island and bamboo homes using no nails or screws have no issues withstanding heavy storms, yet wouldn't pass any USA building code inspection.

....

As for cutting or not, I'd recommended not cutting the stud. But if one does, how likely is the home going to collapse or encounter major failure - low.

Now low isn't zero, but hey, not my home.

....

Could one it better cutting thru?

Sure. Frame it all around - all 4 sides of the cutout - like a window and let that upper stud's downward force travel around the "frame" to the stud below and voila! (Yes, there's more to it, but the general idea.)

Normal foam expands a ton, so if you spray into an area that's boxed in internally, it'll bulge/break the panel. Low expansion foam better in this case unless you can remove 1 full door panel from one side to spray in foam.

1. Yes you can.

https://m.youtube.com/watch?v=Irlv772Pejk

https://m.youtube.com/watch?v=YyVkLa3P1gY

2. Ideally, you'd know how the inside is constructed so you can get foam into all the nooks and such, but realistically, only way for sure is to remove one side's panel, spray, then reattach.

If you drill holes, and have an endoscope, you could peek in that way as well.

3. Otherwise, I'd start with a 1'x1' section, drill the first hole, inject foam, let dry. Then drill the second hole inches away and see if foam has reached that far from the original hole.

Do this a few times and you'll get an idea what hole spacing will allow you to fill fully without gaps.

4. Thankfully.... Craigslist - for sale - free stuff section often has free solid core doors given away that you can use should you want something "better" without wasting a ton of foam money.

   You'd want 3 hinges on solid cores to support the weight.

5. Keep in mind - SOUND IS CARRIED BY AIR! If there's any air gaps around the door edges, noise will leak in no matter to how solid that door is.

You'd want to weatherstrip/seal all 4 edges to keep noise out.

6. Sealing doors in a room that doesn't have a dedicated air return to the heater also means no air flow in or out of that room (air would normally flow under the door out as hot air is blown in from the heater vent).

I'll let you calculate how long three oxygen in a 100% sealed room (meaning it's really sealed well against noise entering) lasts before you die.

If the car isn't fat, I'd just install a slim door.

Otherwise, I'd open up the hole more on the side away from the stud to fit the door.

You could cut into studs, but without further reinforcement, you'll be weakening that section of the wall. Forces from the heavy roof sit on the vertical studs and are transmitted down to the foundation.

Now, houses are generally built "stronger" than they need to be for cases of earthquake, wind, unusually heavy loads, etc, so notching 1 stud is not likely to bring the whole wall down.... But you never know how unlucky you are - you might just happen to notch into that one stud that'll lead to sagging.

....

Strengthen that hole? Just like a dryer vent, you'd box it with metal plates, plywood, etc. secured to the drywall. That'll provide sufficient strength so a fat cat isn't going to fall into the wall, and prevent wall flex.

https://www.youtube.com/watch?v=2Qh14pX3IxA

I'd drop in a wall/ window ac unit that has a heating feature or a mini split. Hook all that up to a few solar panels and batteries and you'll be able to keep that shed temperature/humidity regulated 24/7/365.

...

The big swings in temp combined with humidity in an uncontrolled shed will simply lead to electronic corrosion and failure earlier than later.

But if you don't mind replacing those items sooner than later, whatever.