NO NO NO.
YOU NEVER refer to yourself by ANY suffix (for example, if your name is Ann and you say "Ann-san wa Amerikajin desu" to a native Japanese, to them, it sounds like you are referring to yourself in the third person, like so: Miss Ann is American) so "-san" does not mean "talking about yourself".
San is the equivalent of "Mr", "Miss", and "Mrs" When you attach -san to the end of someone's name, you are indicating respect. However, -san does not have the same level of respect as -sensei.
-kun is used to refer to young boys in the elementary school level. While rare, it can also be used to refer to girls. In high school, a junior girl can referred to as "name-kun" by the seniors.
-chan is used to refer to little girls. It can also be used between close friends. For example, in the movie Taiyou no Uta, even though Kaoru is 19, her friends still call her 'Kaoru-chan,' because she is a close friend.
Senpai is a term of respect between a younger person and an older person. In high school, a freshman would call anyone in a higher grade "senpai", a junior would call a senior "Senpai", and so on.
Sensei, of course, means either "teacher" or "master"