The High Holy Days are the 10 days of Awe, to examine your life and make amends.
Starting on Rosh Hashanah, the “head of the year ( in a spiritual sense, and the beginning of the common Jewish calendar).
Ending with Yom Kippur, the “Day of Atonement.” This is a day of fasting, self denial, and prayer, to “plead with G~d” for forgiveness of self, community, nation, and all mankind.
The principles are sound for everyone. There is no limitation on participation, though most Synagogues are so full they sell tickets to limit the overcrowding.
We do not have formal Rosh Hashanah or Yom Kippur services with our local Havurah, though you could have special meetings with your local Havurah.