The best advice I can give is don't try to move your hands and run the machine fast. Some advocate this.
Practice first just by moving the fabric on a table top. up down, side ways etc to get the feel of motion.
Then when you put the fabric under the machine. Start up but don't move the fabric until the speed is at what you believe is a comfortable pace - about medium speed I would say. then start moving your hands and work to find the balance between the speed of the motor and the speed of your hands in order to get even stitches.. Just doodle on the fabric working to get the balance. It might eventually be fast, medium or slow but should be your own comfort level.