I am a native Taiwanese. I may help you to learn chinese in 3-stages : han-yui pin-yin, traditional chinese character and simplified one.
as I have been worked in Vietnam for almost 10 years,
I may help you to learn vietnamese language.
As 70% of vietnamese words originated from ancient chinese,
it's reasonable to learn these 2 languages both in the same time.
Once you understand Han-yui pin-yin of chinese language and
29-alphabet letters and 6-tones of vietnamese language,
the next step : dictionary online available for you already.
the further step : you start/begin to learn 100-words, 200-words, 500-words, 1,000-words, upto 3,000-words,
the the good results there : you own these 2 languages both.
how about my suggestion ?