For me, I take brisk 2-mile walks around the neighborhood twice a day everyday (aerobic walking). I also enjoy photography and enjoy looking for photo opportunities while I walk. Do whatever works best for you, but the key is to take the first step! You will need good walking shoes and socks to prevent injury when walking for exercise (like aerobic walking).
Go to your favorite search engine and type in “10,000 steps” to learn more about this life saving, life changing program. The information is abundant.