Indigenous Peoples' Day.

As written by a (presumably) white female America. Note the word 'celebrated' below -

How is Indigenous Peoples' Day celebrated?

Indigenous Peoples' Day is more a day of recognition and mourning than of outright celebration. Great ways to commemorate Indigenous Peoples' Day are to educate yourself and others on indigenous and Native American culture, and their contributions and history.

You can also contribute to charities and causes that support indigenous people. Good options include:

• American Indian College Fund provides scholarships for Native American students.
• American Indian Policy Center provides government leaders and policymakers with accurate legal and historical information.
• American Indigenous Business Leaders support the education and development of indigenous-owned businesses.
• Association of American Indian Affairs provides aid in drafting integral legislation for indigenous people, including the Native American Graves Protection and Repatriation Act, and the Tribal Governmental Tax Status Act and the Indian Child Welfare Act.
• First Nations Development Institute supports economic development and education for Native communities.
• Native American Heritage Association provides financial aid to those in need living on reservations in South Dakota.
• Native American Rights Fund fights to preserve Native American rights and tribal resources.
• National Indian Child Care Association provides tribal child care and early childhood programs.
• Partnership With Native Americans aids those living in poverty on reservations.
• Women Empowering Women for Indigenous Nations provides networking, professional and career opportunities for Native American women.

Still the above listing of the groups is a good starting point.

Of course in the late-stage of late-stage capitalism, there's never any responsibility taken for the crimes committed, no accountability for the lives destroyed, and no justice for the victims, survivors, and descendants. Just lots of talk and proclamations.

I would say for those who sincerely want to learn more - best to start in the area you live in now.

There are also outlets online to learn from as well, like Native News Online.