networking 2 computers together by the firewall

I am new to this system. can u tell me how to set the network between 2 computer

Welcome to the forum.
To set up a trusted zone.
Go to security/tasks and run the wizard “define a new and trusted network”.
CF finds your network card auto, so you just have to click ok. You can adjust the IP’s later if you want.
Do the same on both computers.