Get a nylon string guitar with the lightest possible gauge. Learn the chords E, A, C, D, G. Then learn the minor key version of those chords. Then learn the barre chord versions of E, Em, and A and Am. You can get these chord shapes from any gutar book. Practise changing back and forth between two chords; ie play G for a bit, then change to C. You'll gradually build up your hand strength and callouses as you study those chords. If you do this consistently, for say half an hour or more a day, you'll be Voila! You can play 90% of popular songs. Interpret them how you will, and have fun! Id say give the whole process three months and you'll be having fun the rest of your life. Everyday I get a huge amount of pleasure out of the guitar. Of course it's frustrating sometimes, too.