How to connect to my minecraft LAN server because it won't work?

So i looked up tons of tutorials and nothing has worked. We and my sister are playing on the same router and everyone we enter in our ip the server comes up saying there's no connection. We tried direct connect too and it doesn't work. Any thoughts?

Nope. Tried with minecraft servers lans, everything, some suggestions are to try and open your firewall ports and router ports and more things like that.
try searching these two things on google

unlock firewall ports minecraft server
unblock router ports minecraft derver

but in the end the moral is: multiplayer on minecraft is practically impossible XD

If your on the same lan. Then you need to use the ip from server which you can get using ipconfig. For ex. On the server machine you would need to connect to localhost: port and the 2nd machine is serverip: portonserver if you try using whatsmyip or similar sites it only shows the public ip. You need ot use your local ip.