Welcome to the forum. Exercising is a good way to jump start your metabolism. Please consult with your doctor before starting any new exercise or diet program. Adding weight lifting (even light weights such as dumb bells) will increase metabolism as will amping up your cardio. https://www.webmd.com/fitness-exercise/guide/how-to-boost-your-metabolism. This article gives 10 ways to boost metabolism backed by science. They are very easy to incorporate. https://www.healthline.com/nutrition/10-ways-to-boost-metabolism. Really easy things like eat more protein, drink more cold water, drink coffee, lift heavy things around the house, get a good nights sleep, etc. Things we ALL can do. I admire your plan to get more fit as you get older. Let us know how it is going and what we can do to support you.