Steel wool in 0000 size can be used to remove rust from shiny metal parts. Metal polish can be used after that, if needed.
Sewing machine oil for every junction of metal parts that move, or should move, including behind the nose (face) plate, behind the rear inspection plate, and on the bottom. It may take more than one oiling to get things to move freely. Use old newspapers to protect your work surface.
When I work on machine, it will get at least three oilings over a week, lots of gentle hand turning, then I see what may need more attention.
Old old oil has a tendency to get dried out and adhere parts together that should move freely. Oil, heat from a hairdryer, gentle turning, more oil, repeat.
IF you take off the tension assembly, and I wouldn't until you know more about your machine, take pictures of every step, so it can be reassembled correctly. I will try out sewing before taking apart the tension. A fresh needle of the right size, too.
Sewing machine oil is a good choice to clean the exterior.
It's a fun project! Enjoy it, take your time, and you will be sew tickled 😊 to have restored this beautiful machine.