Originally Posted by Homebrew01

You may have a couple different things at the same time. If you hold the right crankarm, do you feel wiggling if you push towards the frame & back ?
If so, do you see the other crank move at the same time, or get the same feeling from the left crank ? Then the BB axle is loose, and may just need a little tightening.
If the crank arm moves a bit, but the BB is stationary, then likely the crank is not tight on the BB axle.
Creaking can come from all the connection points in the drivetrain, and also from saddle, bars, stem, etc that get pressure on them when riding.

So, identify & fix the looseness, then we can tackle the next issue.

Tightening the BB axle is not a big deal, but a few specific tools are needed.
14mm or 15mm socket to remove the crankbolt, AND washer
A crank puller to remove at least the left cankarm.
A lockring spanner and pin tool to adjust the BB.

You can get by with cruder tools to adjust the BB, but a lot more difficult.

Ideally, you'd open it up and clean & regrease, since you'll be halfway there anyway.

Plenty of videos on-line to show you how.