The best advice is to find them, handle them, shoulder them and shoot them if possible. Do it right and do it once and you'll have a lifetime of enjoyment, because most auto loaders being cranked out today will be very hard for the average person to wear out.
What exactly do you plan to do with it?
Every gun will do most things well, a couple of things really well and one thing perfectly. It comes down to a compromise, pick your number one priority and find the gun that does it perfectly, but fits you also, then move to the next item and pick that gun, and so on, eventually you will have a pro/con list for each gun and the rest gets easy.
No compromise here:
Fit, if it doesn't fit, it will be miserable to shoot, next to fire ants in your socks, it can be done, but you'll be feeling it for a few days.
Quality and Finish, pick a gun that is not only attractive but is function(not hard there, most name brand major players are good to go). If you don't like the way it looks and feels, it will not get taken out and used, much like an ugly girlfriend, great at home, but you don't want your friends to see you sporting her around town.
Balance and barrel length, a short barrel is whippy and hard to drive like a 72 Datsun B210 with bald tires on rain slick roads, it can be done, but not like Porsche. You also don't want a lamp post for a barrel either, makes it tiresome to carry and sluggish to shoot, like a 60 model Chevy with a 6cyl and no power steering.
You have to find that balance and compromise, a good friend that shoots or time at a clays range around guys who do shoot and shoot often. You will find the most affable people on a clays course, especially with regards to new/novice shooter, they will let you run their guns and help point you in the right direction, and even help you build the correct form, the basis for good wing shooting or target shooting.
Good luck and choose wisely what works for you, not because one of us clowns recommended it, we don't know you, your build, or how you shoot, get to a range and do not make a haste decision, you have plenty of time and trust me, a new gun is nice, but a new gun that fits and looks good too, is much better!
NRA Life Member