Well Donald, you finagled your way into the White House and completely shocked nearly everyone in my social circle. As a friend and citizen of the country you now lead, I thought I'd give you a few tips for the next four years!
Tip #1 - Stay calm. You got this. Remember who you were before this whole presidency thing. You were the chief sensei master boss on The Celebrity Apprentice. How hard could this gig be?
Tip #2 - Spend some time in DC every now and then! We know how hard it must be to leave Trump Tower - I mean golden toilets, unreal - but it's a little tradition we have in the US for the President to be in the Capitol.
Tip #3 - If and when you go full totalitarian, use those hackers at the NSA to clean up your image on the internet. I'd start with the inappropriately suggestive comments you've made about your daughter. It's like objectively creepy bro!
Tip #4 - Take care of Barron. The poor kid is going to get torn apart at school and you aren't his fault. Hire him some friends like any good father would do.
Tip #5 - Whatever you do, don't let Mike Pence become likable whatsoever. You'll never be assassinated or impeached so long as he is your replacement.
Tip #6 - I know it's not what you expected, the nuclear weapons are not controlled by a big red button that reads "Nuke them". But it's not that way for a reason, just because you are our most cartoonish president, does not mean that you can act like a cartoon.
Those are just a few words of advice. Although I've never been president before so what do I know. Good luck and welcome Don!