Cap'n, with all due respect, Marvel is not the game you wanna learn your fundamentals in. Hell, I'd argue that Skullgirls isn't much better (even though its pacing is a little more, uh, moderate at times). Tag-based fighters (quiet, Kuma! I'm not talking about Tekken, lol) have a different set of fundamentals to work with than your traditional (or semi-traditional) fighter, on top of learning your (basic) 101s for footsies, zoning, poking/counterpoking, blockstrings, links, okizeme/wake-up...the list can go on.
You wanna start off simple-ish, like Kuma mentioned earlier on. Unlike Kuma, however, I believe a game like SF4 is good to learn your basics in. I guess 3S is a good starting point, but be forewarned that the parrying system is in a whole 'nother ballpark.
inb4 Kuma tells you to learn FG fundamentals playing Tekken
>_>
<_<
Smooth Criminal