What is the difference between a “figure” and a “figure float”?
This is an example of less-than-ideal terminology. “Figure” is what I would really call a “graphic”; it basically means insert a picture file. “Figure float” is more what one means by a figure in a paper: it includes the graphic, the caption, the figure label, etc. You should almost always insert a figure float first, then put a figure inside that. Tables work in the same manner. Put a table float in first, then insert the table within that.