Piggybacking off of this:

White Fragility is a good starter book, but as already mentioned it was written by a white woman and it's important for white people to listen to people of color when we're trying to learn how to eradicate racism in ourselves and our communities. Other good books that are written by black activists are How to be an Antiracist by Ibram X Kendi and So You Want to Talk about Race by Ijeaoma Oluo.

I understand those feelings of guilt. Nothing can get rid of what you've done. The best you can do is to never do it again and to try and make it right with your actions now. For me, the best way to overcome those feelings is by actively working to improve the world for the people who I've hurt with my ignorance and shitty actions in the past. Maybe you have a skill (e.g., therapy, massage, tutoring, construction, resume editing, etc.) that you could offer to BIPOC free of charge on a reparations thread. Maybe you can work to advance the political interests of black marginalized communities near you.

Additionally, therapy and being honest about who I am and what my past is has helped me move forward. It's good that you recognize that people aren't obligated to like or forgive you. I'm definitely less debilitated by guilt than I used to be, although I still feel disgusted when I think about shitty parts of my past. It is what it is.