Recommend me a good beginner DIY stompbox

[newbie builder]

Especially since it's your first project, order from www.smallbearelec.com
I never have gotten an order completely right from mouser, it's extremely complicated. From small bear, everything is geared toward effects. You want a 5k linear pot, i'm not sure what the parts number on mouser is, but I do know that those are easy to find on small bear (i'd suggest 16mm because those are easier to fit into boxes). Great luck with your build and I think you've made a smart choice that you won't regret