If they gave you those bumpy types that are very pretty colors and you can sometimes get them in the supermarkets at the holidays, they might not survive. What happens with the gourds is that they need to dry out and they start from the inside. So basically they will either dry or rot. The colors will go away, but that's really okay if they manage to dry successfully. Once they are dried completely you can paint, stain, decorate them and then varnish. There is no way to varnish them when they are still fresh and colorful, they will rot.
Just stick the things on a shelf and watch them. If they get moldy don't worry. If they shrivel up and turn to a smoldering yucky mess, throw them away. If they mold and dry up then you have something to work with. Does that help?