How should connect my light to the wires in these three cables?

You probably have a standard switch loop and a cable that goes out to another part of the circuit.

It's basically this with an extra cable coming in, which would simply be connected by color to the supply cable wires.

You'll have to do some sleuthing with your multi-meter to see what's what.

Take the three wires with the marking on them and wire nut them together. Take the remaining white and black wires and connect them to the white and black wires from the fixture.

One marked black wire is the feed along with one of the bundled white wires. The other marked black is more than likely a feed to another location along with the other bundled white wire. The marked white is a hot to the switch and the black (no mark) is the switched hot.