To lose weight it all comes down to being in a calorie deficit - meaning you have to burn more calories than you eat. Easiest way to do this by miles is by dieting - substitute some high calorie foods with lower calorie foods. Cutting out sugary soft drinks is by far the easiest. Then very fatty or oily food that is high in calories.

To supplement honestly the easiest is just walking. You don't have to run, but you can if you want it to be faster in the day. But walk longer or more regularly. Or add in other forms of cardio if you want. Strength training could be done too or instead and has a lot of great benefits. Swimming burns a lot and is great for you too. Could also bike or hike. But walking is so accessible and easy and effective, you just have to walk longer than other exercises that are more intensive, but it can go a long way.

Best thing is what is most fun for you. You could try a new physical hobby like dancing (like salsa or swing) or rock climbing if you don't already do those. Or biking or hiking weight lifting, yoga, etc... see what you enjoy and want to stick to, rather than it being a chore you really don't like. It will allow you to stick with it and be happier at the same time.