Baby steps, just try to figure out what things mean and make a collection of groups in your bookmarks with some great youtubers that do specific things in a few minute videos. Start with the basic features of the software you have, and that will then be a lot more comfortable to use in the big brother photoshop when you get it.
Maybe we should put our money together and get a new photoshop + lightroom license and pay for a year ahead, and do it 50/50. I think we can run 1 license on "our two systems", who cares if there's a #brexit in between us :P
My biggest tip is to just do it, just start doing graphic stuff over and over again and learn from it and apply what you learned, from short cuts to little tricks, and key combos.
And second biggest is 'non destructive layers, and everything in layers' So you can at any time go back and change text, effects, gradients, maskings, paths, etc.