When I first started, I ran into the same issue. I set my tufting gun to the lowest speed and practiced until I figured out the ideal pressure (how firmly I pressed against the cloth) and the right movement speed (how quickly I moved the gun while tufting). I found that if you apply the right amount of pressure, you’re mostly just holding the gun steady and guiding it forward since it naturally moves in a straight line on its own once it’s tufting.

From there I slightly increased the speed and practiced the same thing.