Creating 2 seperate networks with a firewall?

I have very little experience with networking, so I don't know how to set this up. I haven't found any instructions either. I am trying to set up 2 networks, each with their own wifi and ethernet devices, on one firewall and modem. One "secure" and one "open" network that don't talk to each other. For hardware, I currently have a Netgear fvs124g firewall, 2 random wifi routers, a modem, and an ethernet switch. How would I go about configuring the firewall?

This is what I'm trying to do: https://imgur.com/a/tynGNZZ