Poker is a skill game, and therefore the higher your skill level the better your chance of winning. That being said, making money depends on several factors. The most important factor is what is known as your win rate. That is how many BB/100 hands are you winning for online play and BB/hour for live play. At the lower limits, where the rake is a bigger factor, you need to be winning around 14BB per to be a winning player. As you move up in stakes, that rate can go down a bit. But is normally still going to be around ~10BB per.
The second factor you need to consider is your
bankroll, and this is equally as important as your win rate. Some rules of thumb here include things such as not playing stakes or tournament buy in that is above your bankroll. For either online or live that means don't buy in to a single game for more than around 5% of your bankroll. Don't buy into a tournament for more than 10% of your bankroll. These two numbers might be considered high for some. There is guidance that says buying in for around 2% for cash and 5% for tournaments will make your bankroll less susceptible to variance.
The next thing to consider is training and education. Just as with any skill game, those who have put in the work and have the sharpest skills will be the most successful. I could go on here for a while, but there is a great deal of resources for training out there, seek them and put in the work.
Finally, tracking your progress and your hand histories is important. It will allow you the ability to analyze your game, plug leaks, and make improvements when needed. Online is pretty easy with most sites offering hand history libraries and the ability to use HUDs. Live, you can get any number of
Apps that will provide the ability to take notes after a hand. This is sometimes difficult, and takes some practice. I suggest carrying a notepad and pen and learn some poker shorthand to take notes during and after play. During play note the board cards and the action of all players involved. When the hand is finished you can note all known hold cards.
Good luck.