Working in Vietnam - advice?

My husband and I are moving with my parents in HCMC, VN. They are living there as expats right now, working for a US company. I want to know what is available for work as well as if a work permit is needed. We will have the multi-entry 3 month Visa. My husband is a computer technician and builds/repairs computers. Software and Hardware issues. We are hoping he can start a business or just self-employ himself. It seems as though there is a lot of need for good computer repair, but I want to make sure he is able to work on his own without a work permit, or if a work permit is needed, would he be able to get one without a degree? He has many, many years doing this work, even as a teenager for his school. As for me, I have customer service experience but that is about it. I do not have a degree, but I am looking for options about schooling. Aside from that, what is there available to do? Thank you for your time and help!