The splendor of totality
You cannot completely prepare yourself for the sight of your first total solar eclipse. When totality arrives, you will likely experience several emotions and wonderment at the unspeakable beauty of the corona and the panoply of colors and light. Many people involuntarily scream, gasp, and often cry at this astounding vision. First timers are especially likely to shed a few tears, often followed by sheer exhilaration.
You will be looking straight down the cosmic billiard shot of the Earth, Moon, and Sun lined up perfectly. By celestial coincidence, the Sun and Moon's apparent disks in the sky are nearly the same. This serendipitous fact allows the Sun to be completely covered during eclipse yet also allows us to see the Sun's atmosphere, its corona. The corona is hidden from us all our lives except for the very special moments during a total solar eclipse.
When you look at a total eclipse, you will perceive the blackest black imaginable surrounded by the Sun's ever-changing atmosphere, the corona. The quality of light is truly unique with an amazing show of iridescence, scintillation, and delicate colors.
Another realization that may hit you during totality is that you are watching the solar system in motion. In real-time, you can perceive the relative motions of the Moon around Earth and the Earth around the Sun.
Even for those who have seen it before, a total solar eclipse is an intensely emotional experience. You will feel ecstasy, wonder, and disappointment when it is over. Many people want to immediately discuss plans to see the next one.
A piece of wisdom that many experienced eclipse observers tell those new to totality: do not attempt photography during the precious few minutes of the Sun in total eclipse. Instead, capture the moment with your senses and savor each second of the precious few minutes of totality. What you see will be seared in your mind's eye for the rest of your life. No camera can capture the full range of light, darkness, and colors of the corona and sky. Besides, many people are so awestruck by the spectacle that they are not be able to operate their own phone or camera.
Experienced astrophotographers will make their photographs available online soon after the event. You hope will appreciate these professional photographs, and know that these images, no matter how good, are a pale reflection of what you saw with your very own eyes. You can find certified safe eclipse glasses here.