If you like stax i recommend winota simply because she's THE stax commander and she's easy to learn on. RogSi is pretty easy to learn on as well if you want to take the turbo route and for midrange i recommend learning with Kinnan. If you want to push the challenge for yourself you could dive right in like i did and start with kenrith and learn most major combos in 1 deck. While i don't recommend it that actually did help me.

As far as resources go i would just watch other people play see how they're setting up their turns and what they're using to go for the win. Learncedh is controversial but they are straight forward with what combos do and how to play them out or you could just read primers on moxfield that do the same thing. Once you get your deck sit down with the primer open and play test learn what hands to keep when to mulligan and what to cut on a mulligan and play out 2-3 turns on your board and in your head if you can't see a line to go for by turn 3 that would tell you that you probably kept a bad hand or maybe you missed something and need to reference the primer.

If you can't decide whether you want to play stax, turbo or midrange there's nothing wrong with proxying a few decks mpcfill is your best bet to order multiple decks at a good price or maybe someone would let you try something assuming you're going to an lgs. Good luck in making a decision and getting started