'91 Antelope? Push-button Rapidfire?

The left shifter is for the fronts, and it's pretty much all the way 'up or down' unless, you're running the
'big-big' or 'small-small' combination or like that, so you can 'trim' by moving the FD slightly so the cage doesn't rub on the chain.

The right lever is for the rear derailleur, does it click 5-6 distinct times or lots of little tiny clicks?
Some '90s shimano levers an index mode where one click corresponds to a gear position, and a friction mode that's really a 'micro-ratchet' that has lots of tiny clicks. Good if you're using a non-shimano derailleur, or an older non-indexed shimano. Early 90's bikes still weren't all on the 'group-set' model of equipment yet.