Hi,
I am currently in the process of my Master Thesis. I have already found a topic and approximately know what I will be writing about. The only problem of mine is that I can not find any suitable theory or concept for my thesis. My topic is related to the user generated content and the firm generated content and how they can affect the brand awareness. Is there anyone who could help me with some ideas, cause rankly I am a little lot of what the theory or the concept should be like in order to write a thesis.

Many thanks!

Maybe do a literature review?

Seriously, keep reading and do a detailed literature review. It will help you find a theory or concept that binds your ideas together. Or you will find it isn't possible, then you need to make the project smaller. I am an engineer so might not be the best person to answer but doing a very a good literature review helps immeasurably with any research project.