I'm not American, but here's what I'd do:
Reduce the size of the standing army, and reduce the spending on defense.
Introduce legislation that states politicians (senators/congressmen) must not have any financial interest in the field which they have influence over - no big oil on the climate change committee.
Redefine press harassment to better protect the individual.
Legalise, tax, and regulate marijuana and prostitution. This allows for safer "products", protects individuals, and creates funding for either further investment in the industries, or other much needed areas. It could be self-financing, and help reduce trafficking and abuse. I understand a lot of prostitutes are pimped out and kept on drugs: this could help that.
Direct more funding to (do you call it?) Obamacare and green energy. Subsidies the repairs of places like New Orleans, and send building instructors to train those who want it in construction.
Introduce licensing for baking and investing/trading.
More publicly funded housing initiatives with caveats preventing redevelopment for a set period of decades.
Make legal immigration easier, to prevent illegal migration (from Mexico - I know some people have issues with this) and to raise funds to further prevent illegal immigration. I know a lot of people like the idea of a big fence between themselves and all those Mexicans *gasp*horror*. What, you want us to treat them like people now?
Try to legislate so that more than 2 parties can have a chance at a presidential candidate, and so that you don't have to be rich, or know rich, to rise to prominence.
Oh, and take away all of your guns. You can repeal that amendment and replace it with something not written 250 years ago when you kept what you killed.
But of course, I don't know all of the USA's issues...