Learn about your body. I suggest starting with the autonomous nervous system. Then your metabolic states. Then circadian rhythm. Reconceptualize everything including the way food and exercise affect your body. There is an explosion of research about our biology, and it seems like that will continue for most of our lives.

But, test what you learn on your own body and ask your doc lots of questions. Run experiments on your body over 6-week or 6-month periods, 1-2 at a time, and habituate what works for you. Layer habits on habits Atomic Habits style. For instance, consider buying an HRV monitor to learn your resonance breathing frequency and what your HRV looks like when you are feeling stressed.

Imo, an easy place to get started is to remove foods from your diet that spike your insulin or blood glucose. Combine that habit with a habit to go on a 20-30min walk a day while listening to a podcast about your body. My favorite at the moment are Rhonda Patrick's Found My Fitness and Andrew Huberman's Huberman Lab - they both do a great job to distill the research for practical consideration.