Put your laptop on mains power. You need as much power as you can for working online with video and audio.
Use an Ethernet (network) cable to plug directly into your router. This can increase your internet speed by about 20% - see broadbandspeedchecker.co.uk to check your speed.
Disable 'automatically adjust microphone volume' - if you don't, loud instrument sounds like trumpets can reduce the audio to low levels. Enable 'Original sound' in Settings, which ensures the highest possible quality. Consider disabling 'suppress background noise' as this can interfere with music (Settings > Audio > Advanced).
Only meetings and webinars on the Zoom Desktop Client support stereo audio. Recordings and the Zoom Mobile App don't support stereo audio (audio will be mono).
Use an audio interface rather than the built-in sound processor in your machine. A lot of musicians have these. Can improve audio quality by 50% IMHO.