I suggest that you choose one style or the other.
If you have invested time and effort into the RinkyDink style, you should decide whether to stick with it.
I think that there is more future in the GFX style. And since Serial, LiquidCrystal, ... all use the Print.h style of printing text, you should find it easy.
Just follow tutorials. Run examples. Adapt examples to suit your own project.
Ask for help when you need it.
David.