Not sure about USA for legal things or zoning laws, but unless you are in an area that can be deemed a commercial site, you might get shut down pretty quickly.
Other issues include the problems of insurance and having, or more importantly NOT having a shop front to sell out of. No matter how legit you might be, it is always a bit of a weird thing to be selling out of a private residence, especially if it doesn't have ground level foot traffic frontage.
Not sure about there too, but most wholesale suppliers will not even blink at you unless you have a solid looking shop or a business plan or at least something to say you are not just one guy doing backyard sales and undercutting existing business operations in your town or area (no matter who they are or what they represent).
Hooking up homies is one thing, but trying to sell to the general public might get you more headaches than it is worth, especially if you end up at the skatepark with a car full of product and set up a "pop up shop" and local shops hear about it, because local laws prevent you running something out of your place of residence.
For what it is worth, I have been "helping" friends out for twenty or so years with product, finding things they wanted, buying sale product or things I see have discounts or bulk buys and primarily still buying from every local shop I have been in to just because local shops are the backbone of the local skate scene. I have never gone to a skatepark and set up a shop, or tried to hustle product to unknown kids or adults alike, but many people know me and know I have things and can find things much more easily than they might be able to find them in their own searches. The closest skate shop of any description is an hour away and even then half the time they are out of the good things people want, or others don't want to go there for whatever reason.
There are also others who are doing this that I know of too, some rad people trying to help their own scene, such as
@rocklobster in an Asian country (buying from legit shops to help others too), but I also know of some others who are just money minded dicks, one dude who thought they can save some $$ by not having a physical shop with rent and all the rest of it and load up a van and hit the road, which didn't turn out so well for him in the long run. There are others who stock up on a whole lot of cheap "Brand X" product and wonder why no one wants their crap brands, but again those guys are here for a bit and then gone again.
Not moving product fast enough and having bills to pay, so running deep discounts, or hooking up all your mates at wholesale prices is also not the answer. That sort of thing gets you cut off from wholesale distributors very quickly.
All that aside, think about it, see if you have enough money - at least $10,000 to stock out a shop is about minimum really, $20,000+ is better - talk to sales reps for distributors or contact some via their "Hit us up" or whatever link and see what they say or what you get back.
I would be curious to know how you go with it.
I have looked very closely at what is going on but never deemed it viable financially to open a free standing shop - there are too many others and too many cheap online deals nowdays, so the only way I would consider opening an actual shop is if it was part of something else, eg an indoor skatepark, or a co op business arrangement, as I know some people have, eg wife has a flower shop and husband has a skate shop out the back of it.
Unless you do it fully and have $100,000 to throw at it (half of that is to get through the first 12 months running costs alone) often ventures like this are short lived and I have even seen very long standing and successful skate shops end up having to close because they were just not profitable to run any more.