Adult is the oldest and most saturated business on the internet. Adult content is pretty much worthless these days. Take a look at all the tube sites with streaming porn. Who pays for it any more when it is all available for free?
There are a few websites like Gof*ckyourself.com (replace the * with the appropriate letter) and netpond.com where adult webmasters congregate. You are best to look there for answers and you will find that adult is getting harder and harder to make any money on. Plenty of people will tell you not even to consider getting into adult any more with all the free content and piracy around. I will say the same thing to you. Don't even consider it.
You either have to buy the content, produce your own, or serve as an affiliate in which case some TGP galleries and sample videos may be provided to you. Then when (and if) you refer a paying customer, you get a commission which is typically 50% of the subscription amount.
Not true. There are literally hundreds of thousands if not millions of adult content websites. Each webmaster may own hundreds of them. It's a game of traffic, trading traffic with other adult web masters, and hoping you get a signup. It is harder now than ever to get a paying customer because of all the free content available.
If you want to try making some money at adult, I would suggest you try the Adult Friend Finder group of sites. They have the adult dating, live cams, plus pornography sites all under one umbrella. I have never done porn (I am morally opposed to it), but I did put an Adult Friend Finder banner on one non-pornographic adult-oriented (no nudity, just adult language and jokes and stuff) website of mine and did make some money from Adult Friend Finder signups. They used to pay a $130 commission on signups and I had a few of those. Then the pay per signup dropped to $55 or something and I eventually stopped advertising it.
When you put an Adult Friend Finder banner on your site, you also get paid if the visitor signs up to any of the other Adult Friend Finder websites. If you look on Adult Friend Finder, you will see ads for their other sites like maybe Penthouse. If someone clicks from your site to Adult Friend Finder then they click on a Penthouse banner on the Adult Friend Finder site then signup, you get paid for that, too, even though you didn't directly refer the traffic to Penthouse. You just kind of brought the visitor to the umbrella of companies and you get paid for that.
You are not going to make much--if any--money from Adult. If you have time on your hands and nothing better to do, then maybe you could give it a try. Odds are the amount of time you spend getting into it won't be worth what you make from it.