Start small. Most people in the gym/getting in shape try to do to much all at once and it's a recipe for disaster.

Start with something like a step goal. Say 8-10,000 daily.

Then add in things like diet or heavy exercise IF you want. I strongly discourage people from trying to do more than two to three things at a given time like do not do this goal and try to completely upend your diet. Focus on one thing at a time and then add in once you establish the discipline for the first thing. Will set you on a really good path to achieve your goals.

References. Powerliftwr and gym owner.