You have to find something you love, whether it’s a class full of lovely people or something else, and and then form a habit.
I used to enjoy cycling but don’t enjoy being on the roads on my own so currently do very little.
I used to do a lot of rowing so signed up to a back to rowing course (sadly have to drive 30 miles for water) and bought myself another rowing machine. Even though I am only on the water once a week I love it, highlight of my weekend. Full body workout, non weight bearing. Burns tons of calories. Rowing in a boat with a crew is just fabulous.
I too had gained weight and become less active due to medication and health issues in the last few years. But I quickly shed two stone once I picked up rowing again and I feel much much better about life.
I now row every other morning in my spare bedroom, play tennis. I am crap at it but it is good fun and my lesson is full of nice people.
I go to yoga, again, full of lovely people and I enjoy it even if I am the stiffest person in the room. I am getting better though and have a couple of yoga apps I like so try to fit something in every other day.
Once you get into the swing of getting up a bit earlier or going out to the gym instead of sitting down in the evenings it does get easier.
Don’t try to do too much too soon if you think time will be a struggle, twice a week is a great start.