Ok here is a list of things you must learn by practicing or reading or watching others to become a decent tournament player.
1. Tournaments are played in stages learn the difference to each one and how to play in each one

2. Position play is very important in tournament poker. You will sometimes have to pick up chips by position alone if your not catching cards.

3. When to be tight and when to be aggressive is very important also. Early in a tournament when the pots are small play very tight. When the pots get bigger you play sound but aggressive poker.

4. First Try to cash then go for the final table then go for the win. If you at least cash you can always play another tournament. Then once you cash try to make the final table because theres alot more money so be a little more aggressive here. Once you make the final table tighten back up because each spot will pay alot more. Don't blind out though if you get low pick a good spot and try to get back in the game with a double up

5. Before you start playing tournaments you should know what range of hands to play how to read opponents and how people play different in different buy ins Low buy ins get more fish and so on and so forth

6. Make sure your rested because tournaments can last a long time so be ready to play for hours

7. Have fun and learn somethng new everytime you play. New players can play freerolls for experience but remember these tournys have alot of bad players in them so don't copy them LOL