New to boating and was wondering if i need a pair of fins on my motor.
I have a 1989 125 hp force motor, If I do need them what brand or type should I get?

Zell, if the boat porpoises and you can't adjust the motor to get rid of it you might consider it. That would be about the only reason I'd do it.

You likely won't see any noticeable difference in boat handling, fuel efficiency. You might be able to stay on plane at slightly slower speeds, but in my opinion that wouldn't be enough of a difference for ME to install one.