Ok, but Wikipedia exists, so can I use it in any way?

If you don't even know where to start or how to start researching for a subject, then start with Wikipedia. But DON'T use the information that you find there. Instead, if you find something that you think may be useful to you, Google THAT. If other, more credible websites are saying the same thing or something similar, then you can use it and cite the credible website. If you don't find anything else except for on Wikipedia, then forget you saw it and move on.