Trap music is all about the rhythm. Modern trap typically has very tight, classic 808 inspired drums. Extremely fast snare and hi hat rolls are extremely common.
Very often the entire melody and "music" is just one, simple, rhythmic line. It's normally an extremely percussive in nature type of genre.
It's a great genre of popular music to study because of it's extreme take on "less is more." Many trap songs are so perfectly simple and catchy and have extremely few elements going on... but it's much harder than it looks to get it right in an innovative way. (Just a few thoughts.)
Go listen with that in mind and you should be able to start picking songs apart without much issue.
Good luck!