Review of the "Stickies" is a great place to start. Stabilizing this machine would not be a "beginner" level project. Not that you cannot do it, just understand that you are starting in the deeper end of the pool as it were...
1. you REALLY should NOT use WD40 on the surface It is too harsh a chemical to use on aged surfaces.
2. Sewing Machine oil is the correct thing to use for cleaning this. (yes, oil cleans, just slowly)
3. Along with the sewing machine oil, use LIGHT pressure.
The process to clean this wonderful machine is not fast but worth the results if enough patience is available