Of course conditioning is always number one, because if you are out of shape you can't perform to your full potential. Every day that you workout, start by doing several different ball handling drills, like tipping the ball back and forth above your head, straight out, and bending over below the knee. Putting the ball around your waist in both directions, your head, and your knees. Then there are several dribbling drills that you can you can do with one to two balls. These include going forward and backward on both sides of your body, side to side in front of your body, and figure eights around your legs in both directions.
Repetition is the key to ball handling practice.
You can practice shooting set shots and off of the dribble from several positions on the floor. You should practice shooting after you have done some conditioning so that your legs can adjust to being fatigued while you are shooting. That's more game-like. Passing is best practiced either with a partner, toss-back, or a wall. When you first start out, you can work on tossing the ball against the wall or toss-back in several ways.