How do I know if the meaning of つつ in a sentence is whether "while" or "although"? You infer it just because of the context? or is there any signals before/after that gives you the meaning of it?
I would say it is mainly because of the context. If we look at https://dictionary.goo.ne.jp/word/%E3%81%A4%E3%81%A4/#jn-147598 :
we might be tempted to conclude that つつも can only mean "although" and not "while", but we can see that is not necessarily the case if we look at https://dictionary.goo.ne.jp/word/%E3%81%A4%E3%81%A4%E3%82%82/#jn-147737, in which both "while" and "although" are listed:
I would argue that, in case of つつも, the connotation is leaned slightly toward "although": to me, 働きつつも学ぶ seems to slightly suggest that the writer considers "studying while working" to be an unusual thing requiring extra effort.
I would also argue that "while" in the English language is also often used to contrast two opposing ideas or concepts that nevertheless happen at the same time.