Which Theme will Best For My Education Based Website?

Hi, Everyone I am Lisa Jessie from United Kingdom. I need help to choose for my education based website. I have developed this website you can see here HND Assignment, but now I want to change it's theme so tell me which theme will best for my this website. I am waiting for any good suggestion. If this theme will free so this is very good to me because I have already purchased the previous theme which I have used.