Ignore the former. The Dreamcast version isn't arcade perfect, but it's worth a shot if you're scratched for cash. It will be awhile till we see it emulated, but in the meanwhile this is what I believe will help you out (in order).

1) Pick a character and stick to it: If you're seriously wanting to learn to play, give a character a good week of play. Learn the moves, learn some basic combos so you don't feel like a total button mashing scrub. In this you'll learn a character you like, or decide them to be unfavourable for your playstyle.

2) Watch match videos. It's ok to watch a match or two, incorporate them into your game. Some tactics work because a certain character might have priority over another. Know the current tiers but don't live by them, they just show a difference of advantage compared to other characters ( i.e Chun-Li vs Q )

3. Practice. Play until your can pull even your lowest combo blindly, practice combos vs the cpu to work on taking advantage of an opponent during any given situation. Practice is better against live opponents.

Now, to the finish!