It is so worth it to start obedience training when your pup is young and continue it as they grow older. Took Belli (2 year old female lab) on a walk tonight. I did not have her on leash. I let her walk freely on the bike trail until I saw anyone approaching and then would call her to heel until they had passed. She did a GREAT job. We passed a couple of families whose dogs were walking them and I could hear the oohs and ahhs over her nice manners.
Just wanted to say that it is hard work to train and stick with it, but the rewards are great. If you need help, there are several groups who are willing. Just ask for it.