I am a bit of overweight guy and I don’t know anything about lifting and fitness. I can’t go for strength due to very weak joints. (no loaded squats) I would like to go for body building or hypertrophy training. Some pointers, tutorials and links to resources are welcome.
As equipment goes I only have resistance bands, a bicycle and an outdoor gym.
Also how important is a diet in keeping myself fit?
I disagree with this logic. Try training for a half marathon and not lose weight.
Obviously physical activities burn calories that could otherwise become fat. But no sedentary overweight person is going to suddenly start training for a half marathon and stick with it long enough to get results when your goal is to just lose weight. And that’s ignoring the very high risk of injury from making such a move. It’s a problem of adherence, not physics.