I would start here to port forwarding your Minecraft server.
https://portforward.com/router.htm
If you can connect to your server internally on the same network, then your server is working fine. You now need to show where the connection goes.
Here’s an example. If you send a letter to an address but that address is to an apartment building that has over 100 tennants. Your letter would get stopped basically at the front door because there’s no apartment number in the address. By putting an apartment number in the address, your letter will be sent to the right place.
You need to tell your router to send all traffic that’s on port 25565 to this ip 10.0.0.3, that way the server will be accessible to the outside world.