Assuming that your subwoofer has a jack on the back that looks like the one on the receiver, only marked "input", I'd get an interconnect long enough to reach from the receiver to the sub with RCA plugs on tboth ends and use that.
Since it's new, didn't the sub, at least, come with a manual?
Speaker configurtion for your receiver cn be found around pge 32 or so in your receiver manual, a copy of which can be found
here. It's a big manusl and I didn't scour the manual for additional subwoofer settings. I'm sure you can find it if you look hard enough. The paper copy is easier to navigate.