If you haven’t experienced it, you have no idea what it is nor now it feels..
The only way to accurately describe yourself as "not racist" is when you grant black people and people of color the authority to define what racism IS, based upon their direct experience with it.
As a white person, I have no experience with it, tho I have observed it happening to others,. The same goes for every other white person.
That assignment of authority to define is the crux of the matter.
Of course, some people who have black skin (or other shades darker than white) have bought into white definitions of racism. Take the definitions (or denials) offered by black right wingers. Those definitions and denials come from an eagerness to please and to be allowed to enter rarified political/economic positions where they can bask in the glow of acceptance so long as they don't rock the boat. Fortunately, such people are few and far between.
The primary requirement for entree into the category of "not racist" comes when you are open to listening to black people and people of color who feel slighted by something you have said or done.
In other words, you don't feel it necessary to announce -- whether in black or white or mixed company -- that you are not a racist.
Racist is as racist does. In ALL areas of one's life.
....One’s intent is irrelevant. Because the pain one caused will not be erased by one’s supposed intent. It still cuts like a rusty razor blade, deep and bloody.