Is it okay to exercise in the afternoon rather than the morning? And Can I do a quick exercise before leaving my house?

Any exercise is better than no exercise. A friend of mine could not walk the length of her mobile home. But she tried every day to walk further. Soon she could walk to her mailbox, then to the end of the street, then for a mile. When you exercise, how long you exercise, how hard you exercise are not the important parts. The fact that you exercise is the important part.