@Veladynee fix a personal or a much larger event? It’s tempting to say “Carter wins the 1980 election,” or “the UN is proactive in working with the Arab world to integrate Israel as a new Middle Eastern country in 1948,” but there’s a lot of disaster that could happen there anyway.
Personally? Maybe make it so I could skip forward grades, or change zoning so I’d start high school with my friends from 6-7 grade.