Since my previous answer ended up being directed to what parents can do, I want to add in terms of shyt we can actually change on a larger public policy / social level:
#1. End school segregation. "Separate but Equal" has never, ever worked. Majority Black/Brown schools are always going to get poorer infrastructure, worse teachers, more demeaning pedagogy, etc. than the majority White schools get. Thinking you can close the test gap while maintaining de facto segregation is a bullshyt fantasy perpetrated primarily by White folk who don't ever want to see their children's advantages diminished.
#2. Modernize pedagogy. Bush's "No Child Left Behind" bullshyt set us back 20 years, but teaching had already been going in a stupid direction for a while before that. The focus in inner-city schools on rote memorization, scripted classes, boring-ass test prep even for little kids, removing art/music/electives from the cirriculum, etc. has all made the situation much WORSE. Well-off White families would never accept such an intellectually impoverished sylllabus for their own children, but then they claim it's what Black children need.
#3. Expand the social network of poor Black folk. Having uneducated parents puts you behind, but the Black community in general can't help that because generational educational disadvantages are real. So the best we can do to combat that is ensuring kids from poorer families with less educational background are heavily exposed to role models and peer groups that have had other opportunities. That means diversifying our neighborhoods, getting successful Black folk to move back into and revitalize Black communities while helping poorer Black folk move out of the ghetto. Some states have piloted programs to help Section 8 recipients move into middle-class neighborhoods with strong school systems rather than always de facto ending up in the poorest hoods with the worst schools. That's a step.
#4. Assist parenting among the poor and uneducated. Help parents learn the power of reading to their kids from a young age (in some countries they literally give the parents children's books when their babies are born). Help parents learn the power of TALKING to their kids from a young age. There was one study that showed White kids are spoken to with twice as many words per day from adults as Black kids are. You don't think that's gonna make a massive difference in their own verbal ability when they start going to school? Part of this is inescapable social disadvantages (single parents, parents always at work), but part of it is a lack of understanding that kids should be talked to just like adults are and aren't just meant to be left alone to play or watch TV or whatever on their own.
#5. Do everything possible to increase the status of school in Black communities and enhance long-term thinking. One of the biggest reasons I was as successful as I was in school is because I knew from the age of 5 that I not only wanted to go to college, but I wanted to go to the best college possible so I could become whatever I wanted to be. How did I pick up that desire? I have no fukking clue. My parents don't know either (but both of them are college-educated which certainly helped). I didn't even know what I wanted to be when I grew up, I just knew that going to a great college would give me the most options to make it happen. But the fact that I was so driven to do well in college meant that I was ALWAYS motivated to do my best in school and no one could stop me. I wasn't popular, I was considered a nerd and teased, I got in a lot of fights, but none of that ever dissuaded me because I knew what my goals were and knew they were more important than the idiots trying to talk trash. We need to help kids have realistic long-term life goals that they can really believe in and push to get there despite any bullshyt that might try to trip them up along the way.
There are other important factors like the lower education level among Black parents or the downstream impacts of historic socioeconomic inequalities that you just can't address in the moment, but will have to work for generations to see those even out.
Then there is the shyt like the high incidence of broken families, disproportionate # of black kids in foster care, high PTSD levels in poor inner-city black neighborhoods, and lower-quality health care/nutrition in black communities. Obviously there is stuff you can try to do to address those things but it won't really be much about education directly but more about other systems.
I keep thinking of more factors that should be including (tracking, disability labeling, school discipline systems) but I need to stop there.