Improving bass tone

Turn the tone knob up. It's free, and it will help your bass sound more full, especially if you are playing along with others - either live (unlikely right now) or with a recording. Rolling the tone down can make your technique sound better (it's amazing how turning the tone all the way down will eliminate the finger squeaks and fret clack) but so will practice, and you can really hurt your sound by turning it down too far.

Also make sure you have the volume up all of the way - cutting that can muffle your sound.

Make sure you are fretting right above the fret. And as your fingertips get harder from playing your tone will improve as well - that comes along for free with practice.

Adjusting settings on your amp can help. And adjusting where your amp is can help as well - elevated and away from the wall can really improve the quality of the sound. Practice amps are usually pretty small, so moving it to play and then back out of the way for storage shouldn't be hard, but could really help how it sounds.

Hopefully that helps!