Hello Erica69: Yes, OBS Studio can do what you are asking.
Once you have some familiarity with OBS Studio, the basic arrangement would be to set up a Scene with the following Sources:
- A background of whatever Source type you require - image, video, game, slideshow, etc.
- A foreground Video Capture Device Source of the camera you are using i.e. the camera that is filming you.
The Video Capture Device can be sized or cropped, and positioned using the Sizing handles, and 'dragged' to wherever you want it in the Scene.
Add whatever else you need to the Scene e.g. Audio Capture Device.
I hope this helps.