This one is a no brainer. You need to move your body to expend energy throughout the day and increase your metabolism and turn your body into a fat burning furnace.
What people tend to forget is that in order to lose weight, you need to burn more calories than you consume. This is why it's important to know what your Total Daily Energy Expenditure is. Once you know that you can start to look for ways of expending it daily.
Something as simple as taking the stairs instead of an elevator where possible, or getting off 2 stops early and walking the rest of the journey to your destination, will help get you started.
The most important thing though is that you keep your body moving on a daily basis. A little
bit of movement each day will go a long way over the long term. The NHS recommends that
to stay healthy adults between 19-64 should complete 150 minutes of physical activity per
week. Are you moving that much?
When you feel more comfortable and are ready to step things up, think High Intensity
Interval Training (HIIT) and resistance training to really ramp things up.