I would try using this target I attached below. I have found it very useful in diagnosing any errors on my part. It will let you know what you are doing wrong and you can adjust much easier.
Just print as many as you want with your printer. If you do not want to use up all of your color ink, Do like I do and print in black and white only or better yet print one out and use a copy machine if you have access to one and crank out a boat load of them.
As far as the type of ammo, dont shoot up too much of your defense ammo at the range on paper. Just use your target ammo to get you fundimentals down. Maybe shoot a few rounds to know what they feel like and what to expect, God Forbid you had to use your pistol in self defense. Good Luck and above all HAve Fun!! XD Training target.pdf