In The Watsons Go to Birmingham--1963, what are Chapters 1-10 about?
You are asking for a summary of a lot of chapters; however, interestingly there does seem to be a break in the narrative between Chapters 1-10 and the rest of the novel. It is at the end of Chapter 10 that the Watson family start their journey to Birmingham, Alabama, to go and visit Momma's mother, a powerful matriarchal figure who will, they hope, "sort out" Byron.
The first ten chapters then concern themselves with describing, as Kenny calls them, the "weird Watsons" and their crazy antics. In particular, the relationship between Kenny and his elder brother Byron is explored in all of its complexity. And complex it certainly is, because at times Byron bullies his brother and shows himself to be incredibly cruel, yet at other times, he can protect and defend his brother, showing his love for him. In a sense, Kenny acts as a spectator, charting Byron's acts of rebellion and worsening behaviour and the attempts of his parents to discipline him. Kenny is equally attracted and appalled by Byron's exploits, finding some of his antics hilarious, such as when Byron has his hair straightened and when he freezes his lips to the mirror of their car, but also Kenny is repulsed by the savagery with which Byron bullies Larry Dunn, for example.
Their parents want to bring up their children to have strong values, and in spite of their best efforts, they feel they have not been successful with their eldest son, and so they determine to go to Birmingham and leave Byron with Grandma Sands, a strong figure who will hopefully sort Byron out and straighten his somewhat erroneous behaviour. This is what happens in the first ten chapters and takes us up until they actually begin their journey.