Google...there are wonderbars there. There should be a plate on the machine to help you locate what you need.
It will be a plate with numbers and letters for the model class you have. If it came in a wooden base, you probably need the knee pedal. Not an actual foot pedal. The knee pedals generally plug up underneath. If your machine can be pulled up and tilt back. You should find a port there. For the plug-insie. Looks like you found a superstar
Those old machines are my workhorses. Feel free to PM me with other questions. Or just get my address and send this one to me
Modify to add. You might already have the pedal underthere. It will be under the case on the right hand side. Sometimes that front panel on the furniture piece is hinged, and will open up. They didn't put knobs on them because it gets in the way of things. Give it a good pull. Hinges were usually to the left of the panel. So tug the right side. Also, there were manuals listed for this style/manufacturer listed in my Google search. That can help you with threading, or help you to know should you ever need additional parts. If your panel opens, you will also find a thread holder/supply holder there
handy dandy. I think I dreamed about your machine. Now I want a pink one! Bakelite like yours. Very vintage...late 50's. You might also try an ebay search, to get an idea of the value. I will bet you scored big time on this wonderful find. Oh, and just noticing...you have a left handed machine! That probably pops the value double. Um...unless the picture just loaded in reverse.