I see that I can send and receive, and I also see that I have like 20 or more receiving addresses. And I guess different sending address also. I don't know, I'm not sure.
The sending address is whatever address that have a balance. You can choose a specific address to send from by right-clicking them and choosing send from.
My questions is, what if I need for the receiver to know my BTC address. Like in an ICO. Does Electrum my address, or moves the coins into different addresses?
Mind clarifying the bolded part? That doesn't make sense.
If you only need the receiver to know the address you used to send btc, just see the outgoing transaction in an explorer.