I already had this same problem but since you guys don't support older versions I used 1.16.5 and had pretty much the same issue. So again, I'm not a very techy person but I've helped make a few servers in the past and I follow all the same steps and watch video walkthroughs. I download the client and the server into the folder and once I open the folder I made a run.bat and once I open that it doesn't create anything else in the folder and in the CMD it gives an error. Then I just try and open the minecraft_server.1.16.5.jar file and that created the eula and server properties but did not create a mods folder. I'm just confused because I've done this before and never ran into these problems.