What ports can be closed on the server?

Question

Network administration

Which IPs can be given access only for my IP and which ones can be given access from the IP of the server server itself.
For example, for the database, I gave access only from the server IP, for SSH only from my IP.
FTP generally closed.
For other ports, I do not really understand what is possible and what is not.

Answer 1

https://en.wikipedia.org/wiki/List_of_TCP_and_UDP_ports
then see what you need and what you don't need