Easy does it.
Small changes add up

Here's small things I do.
-NEVER drink any soda. I haven't drank any since I was 10.
-Drink 1L of water a day, I carry a 500ml water bottle with me.
-Don't add salt to anything. That salt shaker you have, throw it away.
-What's the point of desert? I never eat desert, instead I eat a slightly bigger meal.
-Workout in the shower. I do calf raises, did 50 this morning. Trying to reach 100.
-When talking on the phone, brushing your teeth, etc walk around your house or go up and down the stairs.
-Going to the mall? Park far from the entrance.
Don't start a crazy workout routine. Trust me, you won't stick to it.
Instead walk a mile or two everyday to start. Slowly up that.
If you don't want to exercise in public, there's thousands of things you can do in your house.
You can do jumping jacks, pushups, sit ups, squats...Keep it as simple as possible.
Another good tip, keep a journal and write when and what you exercise.
Try to exercise every other day at least.
It's always nice too see people dedicated to bettering their health.
Good luck with your goal