Multiple Users on a Mac, what happens with iPhone

Hey, I'm not new to Mac, but I'm definitely just a consumer-level interactor. Email/Safari, word processing and excel, photography and lightroom, and music production. I spent two years testing out workflows and apps for a creative project of mine, and have a lot of residual junk (like extensions, firewall filters like little snitch). I don't know if I need a clean reinstall or anything but I'd like to get back to square one and install only the apps I know I will work with. Does creating a new user do that, essentially? Any resources you could point me to? Reading up on apple's website hasn't been very clarifying so far. Thanks!