Don’t give your email address to just anyone. If you do, you are risking getting your address on spammers’ lists. There are going to be times you have to give an email address to someone you really do not want to. Aunt Henrietta who sends you 20 a day is an example.
Sometimes web pages will demand one, even though you really don’t want to hear from them. Most of those can’t really tell if the address you are entering is actually real. My favourite is email@example.com. However if you are trying to register or subscribe to something, a valid email address may be required to get access to the information. So, another good idea is to have a second email address you give to people or web pages you need to hear from but you are not sure you trust. This is the email address you should be ready to delete when it gets polluted with all kinds of garbage (AKA SPAM) in its inbox.