The most fundamental thing to know if that if you manage to burn more calories than you take in on a daily basis , then you will lose weight. That's easier said than done, of course. Going for a very restrictive diet and hoping for quick results is a nearly sure-fire way to crash and burn sooner than later. Progressively adapting your nutrition while trying to get more and more physically active is the best way to get durable results.
is something you may find helpful to begin with.
Don't hesitate if you have more questions!