I have problems with talking about myself.
A lot of people have this problem, but really, there is no need to worry. No one in the whole world knows more about who you are than you do, so you are being asked to write on a topic about which you are an expert, the foremost in existence.
As for the first prompt, remember that it specifically asks about qualities and characteristics you have, and then asks you to connect them to how you could contribute to the university. So, to build on Simone's excellent example, if you play the tuba, start by talking about your passion for music, how you have developed it, and how you would like to continue developing it at university, possibly by, say, applying to the marching band, whether they happen to be looking for second string player or not.
The second prompt may be a bit more difficult, as you have to talk about how your family history has influenced you, which may be hard for you to see, especially if you are applying at an age where you are still firmly embedded in that history. Worse, you have to manage to hit all the right notes without using trite phrasing that will be repeated by every other applicant. Your best bet is to just type up the best draft you can and post it here -- specific feedback will be much easier once we have some idea of what your family history and cultural background actually are.