Read 1 & 2, watch 3 & RTM. From there it's just time and hands on familiarity.
1. Guitar Amp Settings and Controls: A Step by Step Guide
2. Vox Amp Settings: How to Use a Vox Amp
3. Vox VT20X 1x8" Combo Amp Review
If all else fails, RTFM here -click on the "documents" hotlink and follow the bouncing ball.
