There is a countdown at the start of the game that allows you to test out all the buttons and get a good feel of the controls before the match actually starts. If you are new to Rules of Survival you need to take full advantage of this time to do that because if you try to get used to the controls during the game you will die very early on.
After the countdown is up and you are on a plane being flown over a map wait until you see an area on the ground that has several buildings before jumping out and then try to reach one of the buildings as fast as you can. Once you have landed quickly explore the building and immediate are to loot any resources such as weapons, gear, and health that you may find.
If you have moved fast and have been lucky and found a weapon you may be able to start taking people down as they are landing.