The image I posted will have female terminals attached to the wiring that will run out the bottom of the mount. The male terminals are part of the relay. The mounts that I have came pre-wired with ~8" of wire from each of the terminal locations in the mount.
I also have a few that just came with the appropriate female terminals to be able to attach your own wires directly without using butt connectors to your wiring and I have seen them come bare so you would need to provide the appropriate female terminals with locking tabs to keep them in the mount.
(Amazon.com link) have the mount point integrated into the body of the relay, but also come with a connector harness that has a length of wire to work with. They are rated at 40A on the normally open contacts and 30A on the normally closed which should be more than sufficient for the low beams.
You will also want to pick up a fuse holder for the +12V feed for short protection in case something happens to the wiring.
I am not advertising for Amazon, but it often is the easiest resource to get decent pictures of things. You can likely buy the same stuff from your favorite auto parts store and even walmart.