Be very aware of pickpockets, particularly in crowded areas and tourist places like Bui Vien and Ben Thanh market, but do not worry about physical crime. Saigon is a very friendly place, not agressive at all. A real danger is the traffic, especially if you are driving scooters. Many bad accidents and unpredictable driving. Stick to Vinasun taxis or uber moto, if you prefer the cheap bikes. Food is great, cost of living is cheap, Saigon is a great place. As the air quality is very bad, a quality face mask (3M, not the cloth or medical types) make a lot of sense if you stay for an extended period of time.
Try 'L'usine' next to the opera house and 'The workshop' a few min down the road, they are excellent places to work.