And one more question.Should my port be on 8333?
I don't know what my current port is.
Why maps like this site:
https://bitnodes.io/nodes/live-map/It doesn't show anything in my country?
After clicking the check node option on the site, I received this error:
(My IP: 8333 is unreachable)
What does this mean? I'm not node?
You are a node. Nodes can either connect to others or let others connect to you. Assuming that you're not portforwarding 8333, then Bitcoin Core cannot accept incoming connections and other nodes cannot connect to you. However, you can still connect to others.
This doesn't impact your usability or utility in any way, but it would definitely be better if others could connect to you.