Primer and sand paper. Get a tack cloth while your at it. Sand paper pack from 3M with 220, 320 and 400. Wet sand lightly between coats and use the tack cloth to *lightly* rub down the frame between coats of paint. If you can find one Paint Spray Can Holder that snaps on the top. The handle makes it much easier to apply. Paint it upside down first, painting the hard to reach places first. Go around the bike twice, painting a light coat first time around then hang on a color coat. Let it dry enough to flip over then hit the missed spots. Dry and wet sand again. The hardest part about painting a bike is getting the last coat on and wet at the same time so when it dries it has a uniform look when it's dried.
Just take your time and it will look fine