Skeet and trap are 2 very different games and everyones opinion wil be different.
Trap = 28" barrel, Full choke and #7.5 shot at about 1230fps and I let the birds get out a bit before shooting (some guys like to break them as soon as they leave the house). With my gun the bird is about 6" (precieved) above the sight plane and the go to pieces.
Skeet = 24" barrel, skeet tube and #8 or #9 shot at about 1150fps and it is pretty much a learned response. you learn where the bird is going and pick it up, break it and follow thru.
Sporting clays is just a lot of fun with most any gun, we shot today with 2 semi-autos, 2 O/U's and a pump. I like #7.5 at 1300fps and a mod choke for most of the courses around me and sometimes a IC works better.
I am not a Pro but like to shoot for fun, I do not get mad when / if I miss and I shoot just as good with my old Camo SBE as the guy with the $5,000.00 gun. the only difference is that when he misses he has a tantrum. When I miss I laugh about it.
So start out with your duck gun and have some fun. the best way to learn is shoot with some guys that know what they are doing and they can give you advice on the fly.