Go over to the Classic and vintage section and search "oxalic acid". It is a way to remove rust without damaging the paint. Service the bearings on the wheels and BB (if it is not sealed) right away. Old grease dries up and stops lubricating. the bearings will eat themselves if this is happening.
See if you can find a bicycle Co Op in your area. They can help you as well as lend you the tools needed to do the job for a small donation.