Before I cut it off at the base, should I spray it with something? TIA

The "brush killer" you see at most stores (containing dilute triclopyr, and usually some 2,4-d) will likely do the trick.

Usually won't hurt a thick-barked tree at those concentrations, unless you start going crazy and spraying lots of the tree's foliage.

Can also cut the main vines at bottom, and quickly paint the bases with triclopyr/diesel mix (or crop oil for diesel).

Virginia creeper??

looks like Virginia creeper

Cut at base. Done!

Agree, cut the base and paint with the brush killer mentioned above. I would not spray the foliage...

Looks like poison sumac. Don't rub against or touch it. Chop it at the ground then paint/pour diesel on the stub.

As others have said, cut the base and immediately paint that cut with Remedy/diesel mix. You're done.

Just cut it, it'll die. As stated before, 5 palmate leaves, looks to be Virginia creeper. Harmless.