How to escape low ELO

i have this recall on some games from the beta (or maybe from some old trailer) where the maps were in the same location they are now, but drastically smaller (with the same assets, building and such of the bigger versions, but with the map...

I just got my first agent unlock and I don't know who to get. Should I get whatever agent interests me or also account for skill? I am horrible at shooters. I've played other shooters in the past but I always sucked at them. The only one I...