President wouldn't be enough to do what I want, not enough power, I'd need to be dictator for a little while. ; )
I'd abolish the Federal reserve bank, returning that function to the Congress. I'd abolish the income tax completely, removing that burden from the citizens and businesses. I'd put the dollar back on the gold standard, each dollar must be backed by a standard weight in gold, and that standard would NOT BE 1/1300th of an ounce which is what a dollar today buys.
I'd close down all social programs, it is not the Federal government's job to be a pension, healthcare provider, housing project, charity, etc, etc, etc..
The government's function is National Security, Basic Infrastructure (interstate highways, national electric grid), Coining money, International Affairs, and that is it! Guess what, with the government only doing what it's mandated to do in the Constitution WE DON'T NEED INCOME TAXES.
I'd pass business ethics laws, with severe penalties, China style SEVERE PENALTIES, because buisinesses have recently PROVED that they must be FORCED to operate ethically; This is a shame because I am all for individual freedom and self regulation, but big business in America has crossed over to being criminal with no-one stopping them.
On the cultural level I would pass standards in practices laws for all entertainment media outlets and national obscenity laws with clear standards and strict enforcement, anybody transmitting over the airways or cable or in the theaters will have to stay within the decency standards or lose their license, the poison that is destroying our society must be stopped cold. Anything corrosive to traditional foundational values would be banned, the filth would return back to the seedy underworld where it belongs, not in our face 24 hours a day 7 days a week. There's no 1st Amendment issue with this, you can't yell FIRE in a theater because that will cause mayhem and possibly death, therefore you can't push filth for the same reason, it undermines society and causes mayhem and death (how many people have died this year over dosing on drugs following this wonderful "liberal" culture).