Hello Mark
It depends on what you want to achieve. Based on your description, it looks like you’ll need a site to site VPN connection. This requires that you have a VPN router at the main office to act as the VPN server, and a VPN router at the warehouse to act as the VPN client.
Alternatively, if you have only a few hosts at the warehouse, you could create a “client-to-site” VPN where each individual computer at the warehouse connects via a separate VPN connection to the VPN server at the main office. In this case, each VPN connection actually terminates on the user’s computer itself.
You can find out more about both of these VPN types in the Introduction to VPNs lesson.
Now such a VPN could be configured using either Cisco IOS routers or using an ASA firewall. You can find out additional information about both of these options at the following lessons:
I hope this has been helpful!
Laz