Make sure to choose the right runes and masteries.

You start Caitlyn as the most adc with dorans blade and a health potion. make sure to keep poking the enemies as much with your headshot (headshot is your passive). If you have a support like zyra and thresh don't feel scared to engage.

If you have picked up a few kills you have to make sure you keep farming, but when you team needs you you have to make sure you are in the teamfights. make sure you tank/support protects you because you are the main source of damage. Don't foreget to use your peacemaker (q) and use your ult before the fights starts for poke. almost always after the fight you'll have it back.

In the late game you can almost 1 v 1 anyone. make sure to pick up dragon baron and your red buff. and push with your team to victory