I am learning to play again. I have been playing for 48 years but after neurosurgery to fix a wrecked left hand (not guitar related) I am learning to adapt to my changed abilities. My advice on technique is to set realistic small goals that you can master in a couple of weeks. It might just be a five second lick, picking or strumming or whatever but you will love mastering that. If you are a singer, then learn a new set of lyrics every couple of weeks too. You don't have to learn the lyrics at the same time as you learn the music but you will probably do just that anyway. If not, you can sing in the shower or the car. If you miss a goal, just leave it for a while and tackle something else and revisit it every now and then to see if you have a solution as your mastery of other little steps advances. Take breaks. If it hurts after 10 minutes, you have had enough, go and do something else for an hour or three. Have a guitar handy so you don't have to make an effort to 'get' a guitar to play. Play for 5 minutes with your breakfast coffee. It all adds up. Make a list of things you want to play. My list has Key. Capo position, Tuning ( I play a lot of dropped D), chord shape, current playing status, and current knowledge of the lyrics, eg OK, Learn, Revise. Above all just have a bit of fun.