Words of advice.
Keep eyes front , back, sides for people who want to rob, scam or befriend you at their pure own benefit.
Wear a man bag, deep over your should across chest with the bag bit ( complete with belongings ) away from the kerbside. Keep elbow firmly over bag. No Wallets to keys or valuables on wrist, fingers or in pockets.
Buy your own drinks and don't accept from anyone else. Seriously. I've travelled there for more than a few days and saw a lot. Don't bring much clothes. Buy them cheap and bargain hard like you know the biz at the Bin Thanh markets. Shirts, shorts and luggage is cheap there, quality better than on the mainland.
At night. When the hoards of mopeds come screaming down the streets, keep your strong arm over your belongings and keep away. Walk with only your group of mates. Better they be drunk than you, as they will get mugged first. HCMC is not safe. By all means go, but keep wary. And sober. Or armed with Muay Thai training.