Without money that can be a challenge. But you could try and do what I did when I was broke and awaiting my flight training. I saved up enough money to take my first lesson and found a good pilot's association at the local airport to become a part of. The instructor was sensitive to my situation and whole heartedly encourage my efforts. He would let me sit in on other people's ground lessons, "Sandbag" on their flights as an observer (With their consent of course), and even gave me some free flight time all in exchange for some elbow grease. I helped out around the Association's office, and spent quite a bit of time scrubbing down their planes. All in all it was a steal. On my weekends I got to sit around and listen to experienced pilots talk about aviation, take free flights, and I got to know every nook and cranny of Cessna 152's, 172's, and 172RG's.