WOW! Do you have a bike there! If by chance you are interested in selling this let me know! Seriously I would like this. Anyway to start all the bearings and beraing surfaces to to be cleaned. This includes the hubs in the wheels the headset, and the bottom bracket. You also need to clean the chainring in front, the sproket in back, ahd the chain. Then you of course clean the frame, fork, wheels, seat, seat post, stem, bars, saddle. Then you re grease all bearings surfaces then reinstal the bearings, relube the chain, inflate the tires hopefully they are not dry rotted. If you have an internal 3 speed servicing the hub with your current knowledge might be a task. Also the cable may be shot. If it is a coaster brake which it probably is servicing this will also be a task. It should be fun learning just take your time. If you need any assistance e mail me.