I currently have a 38 revolver and am considering my first semi auto. I would like something more compact so I can conceal. Any advice would be appreciated. Thanks
You are probably used to the draw, point, shoot method of carrying a firearm since you carry a revolver unless you physically release the hammer each time. Do you release the hammer each time you fire or do you fire double-action? You'll see why that may be important.
In general, semi-auto's come in two flavors: 1911 styles and Glock styles. The 1911 styles have a manual thumb safety that most who carry will carry in what's known as "condition one". This means that a round is chambered by racking the slide which also cocks the weapon making it ready to go, but in addition they then put the thumb safety on so it can't be fired. To fire this you will draw, release the thumb safety, point and shoot. With Glock styles (Springfield XD as well) there are safeties built into the gun but there is no manual safety. Therefore, one can safely holster the gun with a round in chamber and then their technique is draw, point, shoot.
My recommendation is to study both of these general styles and determine which of these two you would like, and then go somewhere that rents what you want to try and reduce your options that way. If you are used to taking an extra step (drawing the hammer back) you may have no problem with the thumb safety. If you are used to just pointing and shooting, that extra step may become irksome to you. I don't know... that's a personal thing that only you can decide.
I personally have both types in my collection. I prefer to carry the type that doesn't make me use a fine motor skill to release the thumb safety. That's me... others differ on this and you may as well.
Good luck on your search.