Do I put it in the gateway or workstation?

When installing services, such as web/db services, do those go on the workstation or gateway?

are there certain things that should be installed on one vs the other?

Don’t use Whonix-Gateway for anything but upgrades and configuring Tor
and bridges. Unless you know what you are doing and/or found that in
Whonix documentation. Everything else belongs into workstation(s).

great, thank you! So I guess that means I can scale memory way back on the Gateway side and give most of the memory to the Workstation?

Yes, details, see:
Platform-specific Desktop Tips