Consider the Sig P250 for a first gun. It is completely modular system and has interchangeable grips, frames, barrels etc. It is a single action long pull trigger. If you learn with it and get good, you can handle any other trigger on any other pistol. The other big advantage is the break down of this weapon. It only has one part to remove to break it down. Turn the break-down lever down and pull it out and the slide comes off and the FCU comes out. Super easy to clean and reassemble.