There are some weapons basics that you should know. For example, there is no hit scan in Apex Legends. This means that you need to lead your shots for them to land. There is also bullet drop, so be mindful of your range when you are firing your weapons. Different weapons are effective at different ranges but also know that if you land a shot that it will do the same damage no matter how far away from them you are.
Something else that you will need to get familiar with are the guns spray patterns. Part of really learning to be effective with your weapon is to know which way the recoil takes you. In the future, we will be providing spray patterns on each weapon page but for now, you can load up the tutorial and try each gun out and look at the spray pattern by shooting a wall.
One thing you want to keep in mind is the varying situations that you will find yourself in Apex Legends. One smart move to improve your game is to have different types of weapons, for example, one for close-range and one for long range.