How to get out from bronze

First try to find some general playstyle guides in which you will find a lot of valuable information on all of the phases of the game. Knowing what to do, what to expect, what not to do is really important. You have to think about your choices every second.

Then, find your favorite role. Mid, Jungle and ADC are the most strongest roles in my opinion because they tremendously control the game. Mid can easily rotate towards top, jungle or bottom to help out the team. The ganks of the jungler are helping the lane to get ahead, and the ADC will carry the whole game if they get farm or get fed enough.

You can check out a ranked solo tier list to find the most overpowered champions in the current meta.

And lastly, an important thing you should be ACTIVELY looking at all the time is when the enemy makes a mistake. That means: walking into a bad spot, casting a spell and having it on cooldown, walking up to take a minion, being out of hp/mana, not using the kit correctly, not warding a specific spot,etc. As the just-mentioned list can get really big, you learn that there is a countless number of mistakes the enemy can do. Therefore, always look for them and try to punish their mistake in the best way you can (idealy not by doing a mistake yourself too).

Hopefully this will help you not only get out of bronze, but help you increase in ranked overall.
Have fun!