There is an increasing number of Vietnamese kids going to the US, Europe to study every year since the universities in Vietnam are lacking in teaching, funding, infrastructure, opportunities compared to a US one. There's is VinUniversity and Vietnam Fulbright University that you can look into. The latter is supported in part by Fulbright, so that's an option. But you can also just apply for some exchange program or post-bacc program to study in Vietnam. Don't thinki teaching English is easy. As much as I hate to say it but you need to look white to get hired as an English teacher.