Most throttle handles have a lever that you squeeze to release it out of neutral. On mine I wrap my fingers around the handle and squeeze upward to shift into forward or reverse.
My trim is a rocker switch on the end of the throttle handle. There is also a gear release round knob down at the bottom where the entire handle pivots. Push it in to rev the engine without shifting into gear. Mine is a Volvo-Penta control but I think most all are similar.
Welcome to the forums and good luck.
_________________
Terry
Current: 07 Crownline 255 CCR cuddy - 350 Mag MPI/B3 "Casi Cielo"
Previous:97 245 Sundowner 5.7GI/SX
Tow vehicle: 1986 GMC 2500 Camper Special 454/TH400