when i tried to pen testing my friend network i succeded to penetrate his master pc with metasploit with port 445
but i scanned another ip with nmap i found only 1 port opened

5101
what is this port and how can i exploit it via metasploit and wat is the payloads for this service
and question about metasploit how i choose the exploit and the payloads when i know the port there's many exploits for port 445 e.g how i pick specific one ?