Need some help for my Cover Letter

Hi guys, I'm writing a cover letter for a summer intern, can you help me make part of it more concise, native and written-language? Thank you so much!

"I know that I do not have much extraordinary work experience in a worldwide company like MS, but I have read all the materials I can find about MS to learn about its business patterns, function mechanism, and job responsibilities; I admit that there is still professional knowledge that I do not understand, but I have started to learn and am making big progress. I am doing whatever I can to prepare myself for this job because I really cherish the opportunity and I want to be a responsible and earnest employee. Years of social experience taught me that Rome was not built in one day. I will be down-to-earth and make progress step by step."

Eric