Physical activity and exercise are very important to maintain a healthy weight and good parameters. It is very important for mental health too.
Use exercise for your endorphin boost(happiness hormone). It helps to have a particular time for exercise. Then it can become habit.
Some people really struggle with this pillar of lifestyle and to them I say - Take baby steps for a few weeks and it will soon become habit.
Another question asked is the kind of exercise to be performed. You can alternated between stretches , cardio and strength training. Do not do things that are not sustainable.
So, go ahead and choose exercise as your tool both for good physical and mental health.