i just have a few questions. and i am going to start off by saying that the only experience i have is from reading. ok well i know how to open a port. in i am pretty sure i know how to connect ot it. but what i wanna know is what ports i should focus on. also i think this is a stupid question but while i am asking are protacals like ftp the only what to transfer files from one computer to another.
Search around for 443 (https). Also,you can transfer with ftp (21),but if you're able to connect thru telnet,you can also transfer files using the correct commands. Port 22 is use for remote login,wich will give you a wider range of options,but it's password protected.
You either would know the login info or use the jtr password cracker and brute force it (jtr=john the ripper). Always do a port scan before anything,sometimes they leave 443 open.