I think I'd hook this person up with an agent who could get the kid doing the round of morning talk shows and the like. Maybe negotiate some sort of reality TV show that follows him around the first couple years of his new life and track his new experiences. A book deal and a ghost writer wouldn't be a bad idea. I figure this will give him some income and a group of people in his life that provide structure, dubious as it may be. An agent and producers will make sure he's eating, has shelter. They'll provide some basic needs to ensure he remains profitable for them as long as possible. Yes, he's open to manipulation and being taken advantage of but hopefully he'll eventually gain enough social skills and resources to extract himself from the situation and live independently.
In a best case scenario, he'll meet people who resonate with him and with his story. Maybe it wasn't his choice, but he put himself out there. He's visible to others. There will be people who want to share their stories and experiences in return. That's where he'll start to build some emotional connections and friendships. He'll make some mistakes in judgment. He'll get burned. But that's not going to be 100% of his experience. He'll make good choices too. He'll make good friends, and not every friend has to be forever and ever. You can be very close to someone for mere weeks or months and then drift apart. That's OK. Some friendships are formed because two people are going through a very specific experience that draws them together.
I guess another piece of advice I would give him is to not to sweat the mistakes. We all make them and sometimes we make really big ones. The only thing he can do is deal with the situation at hand. Face it, as unpleasant as it may be, and start the work of fixing it and moving on. In the midst os that, he should be sure to remind himself of all the things he's done right. We're all a mix of good decisions and bad decisions. If he only focuses on his good decisions and never acknowledges the bad, he'll turn into a pompous jackass. If he only focuses on his bad decisions and not his good, he'll be mired in misery. He should strive to see both sides of himself.
I guess the other way it could go...if the whole Hollywood agent thing doesn't work out...is ending up on the streets (assuming he's in the U.S.). He will most certainly be manipulated and taken advantage of there. From the streets, He'll likely end up in the criminal justice system. Jail would also provide the basic needs of food and shelter. He'd be set up on a revolving door of jail/streets/jail/streets - a cycle that's extremely difficult to break.