UK Student applying to US for postgrad, help! Scholarships, College Life and tips??

So I'm in my 2nd year at Kings, Studying Mathematics and Computer Science. After I graduate I really want to apply to a masters program in America.
However, I have heard how difficult it is and blabla. So I have three questions:

Does anyone have a list of scholarships I would be eligible to apply to?

Will going to america as a masters student be the same as an undergraduate student in terms of culture and campus life, for example I feel like I missed out in the all-american college experience and so a masters program will help give me that (however I have more reasons than just that), so is this true or will being a masters student exclude me from that as I'll be older and a postgrad? :/

Top tips in preparing to apply for masters? I have a year and a half