If you're just starting the game/new character and don't readily have access to players of a lower skill level than yourself then practicing your combos against the computer is really good practice. It'll get you used to performing well with your character to an extent, since they will usually punish you hard if you mess something up. Unfortunately, the computer isn't good for much other than that since they always do the same thing in any given situation.
Something more important than landing combos in this game, especially as a Ryu player, is anti airing. Ryu is one of the few characters in the game that you should never be able to jump in on. Practice anti airing every jump-in in every match you play and you'll make huge progress in your ground game. Know when to use far st. hk (usually when they jump from far enough away to make DP whiff) and when to use DP. If you do a cr. mk and they happen to jump over it, you should almost always have enough time to do a DP to catch the jump in, so always be ready for it. You should never have to block if you know someone is going to cross you up with Ryu. all you have to do is
learn how to crosscut DP, which is essentially going from down forward, down, down back, back, up back + MP. You can practice by going in training mode, Recording the CPU to do a crossup jump in, then punish it. Throw the FADC xx Ultra practice in there two and kill two birds with one stone! If you learn this stuff first you'll be wrecking fools in no time.
