If you want to improve your accuracy and your speed, try shooting at small circles or dots.
Use a sheet of paper with several circles or dots on it. Start at close range and slowly fire a shot at each circle, taking care to observe all the basic shooting fundamentals. When you can hit each one, move back a few feet and repeat the process. Keep moving back a few feet when you can hit all the circles.
To increase your speed, start back at close range. When you can hit each circle by firing slowly, increase your speed a little bit. Keep at it until you can hit all the circles again.
Repeat that process until you are satisfied with your shooting speed.
Don’t try to progress too fast…make sure you are accurate at each distance before you increase either the distance or your speed. With a little effort you can increase both your accuracy and your speed.