the problem you might be having could be either compatibility with mac or that your ports are not forwarded so the outside world cant connect to you IP default port is 25565 rcon port is usually 25575
this is something you would have to do inside your router
but i do not recommend hosting o home computer you should use a minecraft server host
something like
https://shockbyte.com/billing/aff.php?aff=1495for starter server at least and it is super easy to setup.
here is a article on portforwarding for you if you have to host on home pc
https://portforward.com/minecraft/just remember if some kids ddos you its going to effect you connection speed and maybe even upset your ISP