So I just learned to ride a bike and I can turn and curve and all that, but it seems like whenever I ride slow I seem to be swerving more and having less balance so I have to like keep turning to stay on balance. How do I learn to ride more straight at any speed?
Because at faster speeds you will have better balance. It's harder to control a bicycle at 3 to 4 mph than it is to control one going 8 to 10 mph and above.
You also may be looking down too much. Don't look down at the ground. Look straight ahead at least 20 yards or more. Also check things like the proper saddle (seat) height. Most new riders have their saddle too low. Couple of links below. Please read.