The best advice I'd give to a new poker player is be patient and master the fundamentals first. Learn solid preflop ranges, respect position, and don't feel like you have to play every hand. Folding is a winning decision much more often than beginners realize.
I'd also recommend starting at the lowest stakes or in freerolls, protecting your bankroll, and reviewing your mistakes after each session. Poker is a marathon, not a sprint—the players who keep learning and stay disciplined are the ones who succeed in the long run.