I just got this game. I have no idea how it works, or if I'll like it. Let's see how this goes. :S
Yeah, I saw you post in here and was like "Really? =o". Don't worry though, its a pretty great game, although quite difficult at times.
For starters, Attack command is only for finishing off nearly-dead stuff, and will only do good damage on people with a good ATK stat. Focus recovers an amount of SP relevant to a character's SP Recovery stat. Escape works 100% of the time, but drains 3 TP from your 4 active characters.
Each active character will lose 1 TP at the end of battle, and they will lose more if they HP is below full. After running out of TP (or HP, for that matter), they return to Gensokyo. You get them back as soon as you return. And no, you do not get Game Over if all active characters run out of TP.
Your (up to)8 characters in reserve regain SP as if they were using Focus. This is will be very noticeable after you get a few more characters. They also regain HP, but since HP refills after every battle, you won't notice that as much.
As for Level-Up bonuses, I recommend devoting it completely to a character's most important stat, which is almost always either ATK or MAG. In the case of some tanking characters however, (Meiling, and some others you get later) it is best to use either HP, DEF, or MND, depending on who it is. For the character mentioned, I'd recommend DEF.
Skill Point bonuses... it doesn't really matter if you mess up much, since the skill points you spend on one floor will be trivial by the time you get another floor or two into the game. But, since all Stat-bonuses in the game are based off of a percentage, you should still concentrate on a character's good stats.
Hmm... that is the most important stuff to know, so that you won't screw up your characters, and so you'll know the basics of gameplay.