>>331532971
You download the latest vrchat sdk, either 2.0/3.0 depending on the booth model. If it’s any good it’s 3.0. You also download the dynamic bones package (20$ on unity store) or beg an anon for it. Make a new unity project with the correct unity version 2018 4.20f or whatever i forget the exact version name import the sdk and dynamic bones the import your booth package. Usually there’s a unity scene file which can be open and you can just upload it from the sdk window. If not then you may have to drag the prefab into the scene yourself and alter a few things depending on the avatar you buy. 

Be warned though there are older or less popular booth models that come a bit scuffed so if you don’t know anything best to learn the basics. Might be worth learning some basics anyway as you’ll likely want to edit the textures and adjust the shaders to your liking as a minimum.