Good job It sounds like a good way to start your fitness. Maybe you could look into some strength training?
When walking isn't rigorous enough, you might look into the C25K program which seems like a good way to work up to running. Keep at it!
Thanks for your reply, i will start my strength training next week, and i started C25k today,but couldn't run more than 40sec OPS!!! i will keep running until i reach my goal.