Relationship Future

I love my boyfriend but I know we might want different things down the line in terms of marriage, kids, and living in different cities. I’m having a hard time giving myself the courage to have a conversation to discuss it because I want to be with him, but also don’t want to compromise on what I want in life if he doesn’t want the same things. Any advice on thoughts to try on to give a feeling of confidence/courage/completeness to motivate me to have that conversation?