"En" doesn't mean "about". "Sobre" means "about". And "en" means "in".
The point actually is that the use of prepositions in this language works differently from what we see in English.
For example, it would be strange for a native Spanish speaker to hear "yo estaba pensando de algo", while for a native English speaker it would be normal to hear "I was thinking of something", because "of" is a preposition English language consider fine to use in that sentence.
Ir (conjugated) a "any verb" is informal future tense. Voy a beber = I am going to drink Voy a ir = I am going to go Vamos a ver = we are going to watch Vas a bailer = you are going to dance Va a comer = he/she is going to eat Van a vivir = they are going to live
It is always "going" when used thos way.
Vdubs1. Here are two excellent sites that cover verbs with prepositions:
report it. Lenscac is right - "think of" and "think about" are synonymous in almost all cases. The difference is in cases of uncertainty, or when you negate it (when you can't "think about/think of" something). Even then the distinctions are subtle and learned basically by context. Even then, you'd most likely be understood and it probably wouldn't be awkward to interchange them.