If u r 13.......u've pretty much time to spare............give as much time as u can...........u'll surely njoy..........Guitar playing is gr8 fun and a gr8 joy........
c if u just want to play a few songs learn only the songs...........chords........strumming paters bas..........but if want LEARN playing guitar u've to have patience.....
Guuitar playing needs a hell lot of practice............the more u practice u'll tend to perfection( though applies to every field but I feel Guitar needs more).........don't get a amp right now..........cz.......ur sounds in amp. may offend ur neighbors now
get a hold on it and then directly go for electric............
don't worry about the jargons.................u'll get to know it...............
Tutor........any one is better than none.........
Best of Luck..........