Being a tutor (for ten years now!) of two photography course in which students have to produce normally two photo projects, I have seen many different ones over the years!
Here are some notes of help:
First of if you are a beginner choose a project that will help you learn something somehow.
If you want to learn different camera skills and learn in general the make your project a photo essay. (As not all photo projects are photo essays)
Some good photo essays I have seen include;
Local parks or London parks!
Or basically pick a location and document it!
The photo essay can then have and test you on the techniques to produce; landscape, still life, portrait, low light, bright light, fast or slow moving subjects. You can practice quite a bit with a photo essay.
If not a photo essay then a thematic project such as a series of landscapes of different piers around the country (see Simon Roberts for that!)
I see portrait projects quite often, this can be five portraits of friends or family each sitter photographed in two particular ways. This gives the project structure and continuity between images.
Anyway there are many different ways to produce a project, I have seen many great projects throughout my years teaching and I am sure I will see lots more too.