Anonymous visitors can post but not aprove

I am currently working on my very first wordpress website (love it!) but i have a question:

I want visitors to post a message with an image but I want to aprove the post. They have only access to 1 category. Is this possbile within wordpress?

Or a alternative: a pluging that has an upload function together with a textform so people can upload an image and add their story that way.

Or any other solution to my problem..

Thanx in advance