Muscle mass burns more calories at rest but the effect is very slight. Eating back any calories from exercise will absolutely outweigh any slight change in base total energy expenditure.
Focus first of what you eat, then sustainable exercise, then specific tuning of both.
Physical therapy if you have any physical issues at all, massage therapy if you have any chronic pain, occupational therapy if you have specific life skills or mobility needs.
Any preventative screening or vaccines. There are various generic cancer screenings, etc. Get a referral to a dermatologist to do a once over your skin and document any spots of concern.