Check if the squeaks are heard with or without pedalling the bike
If the squeaks are heard without pedalling the bike, it has got nothing to do with the pedals, the cranks and its bearings. So lubricate the wheel hub bearings, the chain and sprocket
Usually its heard when pedalling, and the bottom bracket bearings are the more likely ones that needs lubrication with oil or grease (depending on the design). The pedals bearings are next, and these need to be greased
Never use penetrating oil like WD40 for lubrication (permanent damage to bearings can be the result). WD40 and the likes can only be used to help remove rust/dirtied oil/grease