I recently started getting into Minecraft

so me and my friend wanna play

1. but when we try is always says unable to connect to server
2. We tried EVERYTHING inviting trying to join each other’s worlds
3. it worked once tho, we saw each other has Steve but it was fine
4. but the next day it does NOT work now
5. (ps it was to hard for me to get a screenshot so I took one from the web but this is what it looks like)