No worries.
Different printers have different ways of configuring their network options. For your printer, consult its documentation to determine how to configure a "static IP address". That is the usual terminology, thought some might use "fixed IP" or words to that effect. "Static IP" and "DHCP" are mutually exclusive, so what you're looking for is a setting that is not DHCP. That setting will enable you to enter an address manually, from its front panel control or setup utility.
Before you do any of that, make sure you know how to restore the printer's default settings. If you enter an IP address that is off the wall, you won't be able to communicate with the printer. In that case it's usually easiest to start over from the beginning.
For the Belkin router: Since it's not an Apple product I can't tell you what default range of IP addresses it uses. However, if you go to your Mac's System Preferences > Network, you will see something like this

The numbers adjacent to IP Address are what you need to know. The above screenshot indicates the router assigned this Mac an IP address of 10.0.1.3. Whatever they are in your case, make the printer's IP address the same except for the last value.
DHCP addresses are assigned by your router to devices on your network sequentially, beginning with the IP address of the router itself. In the example I cited above, notice that the router's IP address is 10.0.1.1. IP address 10.0.1.2 was assigned to something else, then the Mac was assigned 10.0.1.3. Following that addressing scheme, an IP address of 10.0.1.100 would permit 98 other devices to be assigned IP addresses by your Belkin router before any of them would conflict with the printer. That should be sufficient for most small home networks.
If your Belkin doesn't use 10.0.1.x addressing scheme then substitute the values it's using for the first three.
After you do that, you will need to add the printer again in System Preferences > Print & Scan, because the printer will no longer reside at its previous address. Delete the old one.