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?
You can’t outrun your diet.
In your case, you can’t out lift your diet.
You can lift weights 10 hours a day, but if you do not change your diet, it won’t really matter.
You need both. Just dieting will lose muscle mass as well as fat, resulting in lower metabolism. You’ll then gain weight again, diet again, losing even more muscle mass. Years of this will leave you in a really bad state. Lift weights, and eat a healthy diet that fuels your muscle.
I think op should be asking “how do I weight train as an overweight person with bad knees?”
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.