I NEED SOMEONE'S Help Really Really BADLY?

Me and my friend want to play Minecraft together. But Minecraft itself won't let us play together. Whenever me and my friend tried to join each others server, it doesn't work. Minecraft tells us: could not connect to server. Please Help! I WILL GIVE A LIKE AND RATE THE BEST ANSWER 5 STARS! (PS, I will also give you a cookie)

Added (1). I MEAN We're TRYING TO CONNECT TO EACH OTHERS SERVERS! That means I try to make a single player server and open LAN and SHE tries to make a single player server and open LAN! On single player!

Try another sever?

If you are on platform, just give it time, both of you sign out, or you can just leave and reload the world and try again or have your friend try to host it! Hope I helped