Ok, well, pick up most any O/U you can find that's used ...or borrow ...or club gun or whatever until you have at least say 10 range trips ...4 lines of Trap per trip ...so 40 rounds of Trap..../ shoot as many guns as you can - a lot of shooters will let you put a few shells thru their guns if you're a good guy around the club.
I've never met a Trap shooter that didn't have at least 5 Trap guns...so just talk to some of the guys ....they may have a few "training guns" they keep around for training new shooters, grandkids, etc and they might be happy to let you shoot it a few days...( heck, I don't even like Trap ...and I have 3 dedicated Trap guns - a pair of Citori XT's in 32" and a BT-100 in 32" )...
At that point you can probably evaluate some of your fundamentals ...and see what kind of gun you want...length, balance, etc.../ then consider investing in a gun.
You need to understand and evaluate the concept of a "parallel comb gun" vs an "angled comb gun"....and how and why they might fit you best. Both of the guns you mentioned in your original post are angled comb guns...and typically neither of them will shoot high enough to float a Trap bird. But you need to hang around the gun club ...and read ...and figure this kind of stuff out before you buy.
If I had to pick one gun - that you should consider it would be the Browning Citori XT Trap in either a 30" or a 32"..with a parallel adjustable comb. Look for a good used one / learn how to evaluate a used Browning Citori ...at any gun club in the US - there are a dozen or more Citori XT's for sale ...( and don't get confused in the Citori liine of guns - there are about 29 models ) ...so not just any Citori will be ok - and some have angled combs and a few have parallel combs.
And don't forget -- have fun with the process !