I just bought one that measures forward and reflected power and at the
bottom is the swr calculation.

Is the antenna's swr where the two needles meet?

Also the switch on it for 2 meters says "144 mhz" So I should tune my
radio to this when tuning? What if I want my antenna tuned for 146 mhz.

It is an MFJ unit. Yes I did read the instructions but they left alot
to be desired for a first timer.