Therefore, you should check the blower motor resistor first. If it's faulty, it will need to be replaced, not just the fuse. There might be a fuse related to the *circuit* supplying power to the blower motor resistor (and therefore the blower itself), but that's less likely to be the problem than a failed resistor.
Consult your owner's manual for the precise location of the underhood and interior fuse boxes. However, focusing your search on the blower motor resistor will likely yield the answer to your heating/AC problem more quickly.