We are about to touch May 2016 and I want to know what is working best in AM? Of course there are lot of traffic sources, products, networks and stuff but for a beginner what do you think should be the best way to start? Pop-up or Facebook or Mobile or anything else?
All of the mentioned can be divided further into many sub-categories and verticals, as a beginner you should pick one combination and learn the basics while running just that, then once you feel confident about what you are doing, you can decide how and where to move forward.
To learn the most about tracking, optimization, bot detection etc... the best is to promote low paying offers in less developed countries - so Africa, South America, some Asian territories etc ... The lower paying offers are usually sweeps and pinsubmits like antivirus, video content, games etc ... The fastest to start are pops. So if you want to start ASAP, the best combination for you is to pick mobile pops and push sweeps or pins.
NOTE: obviously, this is the most popular choice for newbies, from the very same reasons I already covered, so expect a lot of competition
Getting a campaign into profit with this setup will be rather challenging, but you simply have to start somewhere and its gonna cost you some money no matter what you do - consider it the cost of business.
The community on STM is very friendly and helpful, so feel free to start any question along your way 
Welcome to the forum again.