Honda lawn mower wheel drive works, but needs adjustment, how?

Cathy, there is a way to adjust belt tension on some models whether it is by the cable or a slotted bracket where the idler wheel is mounted, depends on make and model. If you have your manual check in it for belt adjustment. Could be stretched belt, stretched cable, worn/oil on pulley, seized tensioner, stretched/broken spring on tensioner,etc.
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Drive belt Ok?

There is an adjustment to tighten up the drive belt tensioner pulley. You should be able too see it after you remove the safety shield. Tighten adjustment nut to snug belt.

the should be a plastic cover under the engine

The drive belt is off the pulley, you will need to check under the deck and possibly remove the cover on top of deck to put it back on.

Typically self-propelled mowers are propelled using the front wheels, which only turn forward. Pulling the mower back while the front wheels are turning will damage the drive gears. It's best to raise the front wheels slightly off the ground before pulling back.

SOUND LIKE THE TRANS IS WORE OUT

It might be that a cable adjustment is needed to pull the drive wheel/gear into contact with the driven wheel/gear.

Check the drive shaft bearing closest to that wheel.

either the wire going to the transmission is not tight enough and need adjustment or belt needs replaceing