not dumb questions at all!
i highly recommend getting good at sourcing from thrift stores and such til you're making enough to scale. it won't take long if you hustle and don't but a ton of trash. just send boxes as often as possible to get yourself buy box eligible, which will definitely help with your account health.
here's the thing - what you're talking about it called gating. a lot of brands require 3rd party sellers on amazon to get "ungated" by asking if they call sell their brand. others require an invoice for 10 units of a specific brand. some 100 units, some 200 units. the good thing is when you're scouting, Scoutly will tell you if you are restricted when you scan an item. the trick is to then flip over to the SellerAMP app and scan it again, then click the "Manual Ungate" button. this will tell you right then and there if you can just apply or of you need to get the 10 units. will help you not buy stuff you can't immediately sell.
the more you sell, the less you're gated. apply as you come across brands that allow it, even if you aren't going to sell that book you scanned. just apply. there's some tricks to getting ungated in dvds and cds i'd be happy to share, but unfortunately there are no shortcuts for book brands.