If the hole is in the middle of the tire, you can do one of these things:
Apply a tube patch to the inside of the hole, and add a layer or two of electrical tape, or duct tape. (The glue that will stick to a tube is not so very good to stick to the tire... different material.
Or, you can cut a small square of cardboard from a tube box, and tape it in place. It will stay there, protecting a potential weak spot, until you finally need new tires.
If the hole is in the sidewall, and you do not wish to replace the tire right now, apply several layers of electrical tape on the inside.
Tips: Remount that damaged tire on the front wheel... it will take less punishment there.
Also, there is a product called "Shoegoo," one can find it at building supply stores... it will fill the hole, and stick FOREVER. (I patched a cut on the surface of the back tire of my Yamaha YZF 600 about 3,000 miles ago... and it is still there!