So, I watched this video where this guy made a .bat file for the server, I did everything like so. I made a notepad with @echo off
java -Xmx4G -Xms1G -jar Minecraft forge server 1.12.2.jar nogui
pause
And did the save as, then all files and added Start.bat, and it made the launcher thing, then I double clicked the start.bat and it opened the window saying "Error: Unable to access jarfile Minecraft
Press any key to continue . . ." and after pressing a key it closes and that is it. It simply didn't work. I really need to get this to work somehow, even a very small mod with my friend lags like crazy, It's really annoying.