My new “fair” goldfish?

Ok, so I won a pretty little goldfish at the fair last night. I named her/him Zipper after a particularly endorphin-inducing ride that we went on. Last night I put him in a small 1 qt bowl, but this morning I transferred him to my five gallon tank. I set the tank up this morning, so Its going to have to cycle with him in it. The tank has gravel on the bottom(red white and blue), a rock and two fake plants, does it need anything else? (Do NOT say more space, or gallons, I’m not buying a new tank just for this one fish from the fair. Can he eat Tetra-Min tropical fish flakes? If not, can I feed him bugs? Ants/spiders and such? He’s red and white, and I think that he is either a small Pond Comet, a fancy goldfish, or just a particularly nice-looking feeder goldfish. I’m going to another fair next weekend and I know that they are schooling fish, should I get him a buddy?
I have a filter that is intended for five gallon tanks, so I’m good there.