Ok, so...hear me out.
I've only been practicing for a week with the game, but the dumb arcade games help a LOT with things like muscle memory for where the frets are, and which string is which. If all you're doing is Learn a Song, you're doing yourself a disservice. Play some of the arcade games as a warmup. They're frustrating ar first, but boy howdy, when you start getting a streak with that little pink cowboy without looking at the strings... chef's kiss.