start by studying the rules of poker, then something about strategies and after that you can try watching some tournament analysis videos on youtube.
Here on the forum you can search for any topic you have doubts, or simply browse through the strategy section and look for something that can help you.
Before I can help you with information I need to know what your knowledge is, what level of game you are in, what values you play, what modalities you like, if you are starting and don't know anything I advise you to start with MTT or SNG.
The basic thing about any game or type of poker is knowing how to use the position to your advantage, observing the texture of the board, and doing good bankroll management.