I have seen translation/usage of this as "will" or "am". So is there any rule/hint that will tell me when to interpret or use it as: will or am?

"Vais" is the first person singular of the verb "aller" (to go).
"Je vais bien" literally would translate as "I go fine", in French that's correct but in English that doesn't make much sense, so to express better the idea it translates as "I am fine" but the verb doens't mean "am". As you know, every language has its own ways to express certain ideas or concepts and sometimes translated into others in a literal way don't make much sense.
The verb "aller" is also used to express the future and in this sense, more than "will" it is more equivalent to "going to", example:
...I am going to sing a song... ...Je vais chanter une chanson...
Greetings

Thanks Al3! Now that makes sense.

My pleasure.