How to teach myself guitar? I'm clueless.....?

Well I have had a guitar for about 2 years but I have no idea how to play. My parents won't get me lessons because they claim I don't show enough interest but I just don't know what I'm doing. I can not read music so I was wondering how can I teach myself guitar. (I have an acoustic and electric guitar) Also I was wondering.... I was looking up tabs this one time and I could not understand them they were different than the ones i was used to seeing I was wondering do those tabs have to deal with different tunings?