If I were the president of the United States, the first issue I would try to fix is the systemic racism and prejudice that plagues society.
It is essential that people are equal within this country, a country of freedom. There will be no peace without justice, and the people will not be happy and this country will not be successful without equality.
There should be no prejudice, discrimination, or segregation based off of gender, sex, religion, ethnicity, nationality, background, or sexual orientation.
This is the most important task a president can complete. A discrimination-free society will be a more functional-- no riots, no need for protests, more diversity in politics, and, hopefully, better systems within the state.