i know this is an old thread, but i made a living from online and live poker tournaments (not cash games) for 3 years and can shed some light on the topic if anyone is interested
i can say right off the bat, it is not as easy and straight forward as you may think as a beginner. the more you learn about the game, the more the bigger picture of it all changes.
its a very cryptic game in the sense that it is deceptively simple to play, but there's alot of maths and psychology behind every single decision made at the table, and one single mistake can cost you a days work.
it can be boiled down to a game where the winners are those who have the sharpest wit (in poker terms), and those who makes the least mistakes.
i can safely say that online poker is not worth the time investment anymore since amaya (a las vegas gambling corporation) took over pokerstars in 2014, they have completely changed the tournament schedule, the payout structures, raised the rake on everything (amayas cut), introduced a casino and sports betting portal along with some gambling versions of poker (spin&go) and generally made it more of a gamblers game than a strategists.
a few years ago it was possible to just play on pokerstars and make a decent living from it, but nowadays you'd have to branch out and play across 6 or 7 diferent sites, it is still possible but much more of a ball ache.
but my advice to anyone looking to make money in poker is, that you need to gain momentum in your learning in order to retain the information needed in your head to be able to succeed at this game. playing 3 days a week wont suffice. you'd need to spend 3 hours a day 5 days a week minimum, studying, playing, reviewing hand histories, and experimenting with your knowledge to develop a solid bankroll management plan, sharp & creative ingame strategy, and endurance (its taxing on the mind) in order to make some money... and thats after you've internalized the basics to the level of unconscious competence. not worth it unless you're genuinely serious about it.
having said that, if anybody is interested in starting, i would recommend playing for a couple months to get acquainted with the game, then reading "the mental game of poker" by jared tendler & "kill everyone" (cant remember the author). these are the best books out there on the subject imo.