I have been taking photographs for a very long time; I think since I was 8 or 9 years old. Initially I borrowed my mother's camera, and then I was given a plastic camera as a Christmas or birthday present.
I recently Googled "1960s plastic cameras" and quickly recognised "my" camera. It was a Diana - or it was one of the many Diana clones. It had a blue top plate, used 120 roll film, and had basic adjustments for aperture and focus distance. I remember that it quickly got damaged and started leaking light. However my research found that this was a common problem and many of these cameras were covered in black tape to stop the light leaking in.
If you're interested in reading about the Diana camera, here are a couple of links:
Today you can still buy a Diana camera (now labelled Diana+) as a retro "toy" camera with a nostalgic "dreamlike" quality to the photographs. They are somewhat more expensive than the original Diana though.