Thanks !!
It's tricky to reason about profitability in startups, because most "successful" unprofitable startups choose not to be profitable, usually in order to buy further market share.
The big difference between a seed round and an A-round in practice seems to be that valuations for seed rounds are usually casual (and sometimes nonexistent, deferred to the A round), and A-rounds always come with a valuation.
Generally, a seed and (sometimes) an A round are things you could imagine getting without being in immediate striking distance of real profitability.
By no means is that complete, but that should give you a primer, and I learned about it from other startups that successfully have raised funds. (I was in the dark too at a point. https://news.ycombinator.com/item?id=4064276)
The other big thing is just to get out and talk with other founders near you. I found (at least in our community) they were very willing to share information over a beer or soda.