Tape some painter's paper to a wall and give it a shot. Gun's gotta be moving from before you squeeze the trigger until after you stop the sweeping motion of the gun. Also have to have the right size tip for the thickness of the paint you use. The approved tip ranges are listed on the paint you'll use. Also need to hold the gun the correct distance from the surface to be painted; not too far away (paint gets 'dusty'/kind of vaporizes into nothingness) or too close (the paint will run and sanding paint is a huge, HUGE pain in the rear). Also need to hold the gun fairly perpendicular to the wall. Pro's make it look easy because they've had a ton of practice. The higher the gun pressure the harder it is to properly control the paint. Those Wagner guns might be easiest to use. I own an entry level Graco rig and a decent quality Graco gun and tips and found that getting the right pressure (I have no pressure gauge on my rig) and the trigger squeeze and release were the hardest things. Squeeze the trigger with confidence and when you release it, do it quickly because slow releases tend to cause the paint to dribble out at the end of your stroke/pass. Good luck!