Cleaning hum from already recorded tracks will always be a balancing act compromise.

All kinds of noise reduction and multi band compression are available
at price points hobbyist & semi pro recordists can reasonably afford.

At most basic you can manually edit unwanted noise from the silent gaps on each recorded track
but will still have to put up with it underlying the music performance,
certainly if it's not at a low enough level to be masked by all the other instruments..

At worst it can sound unnatural if the edits are too apparent.
Sometimes it's best to leave in a certain level of the noise
to maintain a consistent sense of performance environment in the 'silent' gaps.

That's why it's best to try to eliminate distracting extraneous noise
from the equipment chain before pressing 'record'.

Good quality leads and connectors, properly matched impedance pre-amps & DI boxes,
modern building wiring to defeat earth hum loops, or adapter boards with line cleaning filters.
Foot pedal nopise reduction/suppressors - whatever it takes to ensure as clean a recording chain as possible.

But we know and must accept that real world clubs and venues are not great for on the spur of the moment recordings..

A healthy diet of listening to vintage classic live bootleg recordings
can help put 'noise issues' into perspective.