Hi Carol, :welcome: to TBN.
You have come to the right place. I've got a BX2230 also.
First MMM is mid-mount mower.
The round knob behind your left ankle has adjustments for the height of the mower. The marks may not line up perfectly, but as you spin that around and feel the detente "lock" it in position, you'll find that each setting lowers the mower by about 1/2 an inch. This knob should be very firm. I got my tractor last September and found that it wobbled all over; was broken right off the frame. As a result, my mower dropped right to the ground every time.
The knob behind your right calf is to adjust how fast the 3ph goes down. Oh, and to answer that last question, you can't keep the 3ph up while you lower the mower. The 3ph supplies the lift to the mower via a rod under the seat and platform.
OK, the rest of the levers:
Left side, outside: Choose the mid pto, rear pto, or both.
Left side, inside: Engage the selected pto.
Right side, inside lower: Hydraulic lift, 3ph & mower
Right side, outside lower: 4x4
Right side, outside upper: High or low gear for ground drive
Right side, inside upper: can be cruise control or maybe 3rd hydraulic valve.
Right side pedal: hst
Right side pedal (further forward): brake
Left side pedal inside, little stick: brake lock (apply brake, push this, release)
Left side pedal outside: differential lock.
Take your time, go drive it around the yard a little, enjoy! :thumbsup: