I'm a young, athletic, outdoors kind of guy. Problem is I don't make a lot of money (about $25,000 after taxes as a firefighter/paramedic). I'm looking to do something different and camping is getting kinda old. I'd like to try out mountain climbing or go backpacking. Ideally this would be something I could do either by myself or with 1 or 2 friends with minimal cost for each of us. Ideally I'd like to just start on some trail up in the mountains or wherever with nothing but what I can carry on my back and just go for a few days. Any advice as to how to go about this or necessary skills I should pick up on?