What is the best strategy to reach atleast top 5?

Can anyone teach me?

If you are not good at building or shooting, I would suggest you to camp wherever possible. Do not engage with enemies unless they are bots.

If you want to get some kills, try third-partying people who are fighting. This can also be used to get a win. When the last two are fighting, try getting both to low health and kill whoever remains.

Do not run without cover. Rotating along the sides of storm is the best way to get to the next circles. Make sure nobody is approaching you from inside the storm.

Always have a launchpad with you, when someone is close to kill you, and you realise you can't do anything, try launching somewhere else. Make quick turns so that the enemy can't hit you easily.