Rosh Hashanah commemorates the creation of the first human beings (Adam and Eve)
On this day we as human being have a chance to renew our self by trying to be a better person in the coming year, this is a time for reflection Chashbon nefesh (account of the soul) to go deep inside and see our potential to grow and renew our deeds and action.
Rosh Hashannah starts in a new moon of the Hebrew month of Tishrei.
Our calendar is based on the moon, and similarly the Jewish people are compared to the moon. No matter how dark life seems for the Jewish people, we must know that the "light" is already waiting to reappear. Jewish history is an ongoing portrayal of this principle. Also, unlike the sun, which is always present in its fullest form, the moon progresses in stages until it is full and radiant.
A Jew must look at life as a constant process of growth and development. Tiny beginnings can grow to their fullest potential, and even darkness can be overcome.
On Rosh Hashanah we blow the shofar.
The word shofar is related to the Hebrew word, l'shaper. The word l'shaper means, "to beautify or to change for better." The call of the shofar reminds us each of our own calling, the calling to live beautiful lives. Why does our King decree the celebration of holidays and the performance of mitzvot, commandments? Only as a way to guide us in the process of beautifying the world and ourselves we live in.