G'day Pete and welcome to Chordie.
The Fender G-Dec sure has a lot of features and functions, too many for my liking. That is the main reason I sold mine and bought an easier amp to operate. Although the G-Dec may suit you better than it did me, try it out first and make your own mind up.
For backing tracks these days I use an IPad with "garage band" app installed. Works for me.
I'm sure someone will come along soon with better advice, plenty of very knowledgable folks on this site.
All the best
Bushy