What ship should I get?

I'm having trouble deciding which ship(s) to buy. I can't choose between the Vesta line, the T6 Fleet Avenger, Kelvin timeline ships (which one?), the 26th century ships (which one or entire set?), or the 31st century ships. I have a Tactical Officer on the Federation side and am kind of a noob so I have no idea what terms such as EPtS or Drake builds mean.

Thanks in advance!