I've just been thrown into the Mac world on my summer job. We have two Macs in the office. Apparently, we are set up on WI-FI. How do I access the files from one computer to another?

I realize I haven't given much information, but I'm in desperate need of help. I'd really like to avoid looking like an idiot : )

In the top menu bar find Help, then select Mac help.
Enter file sharing for search terms. Read a couple of the help topic articles.