To find all of the controls, start a match, click Start, and look at the controls. Now that you know how to sub, block, click O/B alot, you can actually learn how to play the game.
Storm 4, like all the other games, isn't too complex. Once you get down the basics, it's pretty universal to every character in the game. For example, every character has a neutral, up, and down combo, a throw, a counterattack, one ninjutsu, a secret technique (maybe a linked secret technique, depending on your supports), Awakening, etc.
Some tips:
1. Don't sub unless you have to. You only have 4, so use them sparingly. Whoever runs out of subs first is likely to get destroyed.
2. Learn how to combo cancel. Some (maybe all?) characters can combo cancel. During your combo (could be neutral, up, or down), the enemy character is in a state called "stagger," in which they can't do anything except sub, if they have them. At that point, you can cancel your combo and start it again without them be able to get out, or making it very hard to get out of.
3. Don't use Awakening. This isn't so much a tip, just that no one likes that guy that always Awakens.
4. Whenever they're knocked on the ground, use that time to gain some chakra. Or if you counterattack, you can gain some chakra then, too.
5. Make use of your throw and counterattack. Don't spam them, but don't be afraid to use them.
6. Chakra dash to start your combo. Click Triangle/Y to chakra load, then click X/A to dash. If you hit them, they're staggered and you can start a combo (assuming they don't have any subs).
7. Chakra dash to reset your combo. Once you hit them a couple of times, you can chakra dash into them again in order restart you combo. If they sub and you time it correctly, you can chakra dash into them after they subbed, allowing you to start another combo.
There's more, but you can watch a bunch of YouTube videos to find more out. I'm not even that good, but those are the things I know about. Storm really is a simple game to learn and be ok at. If you want a super technical game that's incredibly hard to become good at, play some Melee. lol