"I am hoping to see measurable results from this quest"

I will be turning 70 this year and I am very out of shape. I weigh 158 lbs and I am 5'4" tall. I have worked in an office job for the last 50 years, so I have spent 8 to 10 hours a day sitting at a desk. Right now we are in the middle of the COVID 10 pandemic and here in California, we have a stay at home order so I have been unable to have the initial testing done. I have a home office so I am still able to work, and I did buy a standing desk. The biggest problem I have is low energy and hip pain which I'm sure is from sitting too much. I am hoping to see measurable results from this quest. Sorry, I don't have a better picture.