With ezreal,in lane you would want a support that can take a lot of damage so you can give the enemy a lot of damage,usually Soraka is the best support for ezreal,depending on your play style,but some prefer Blitzcrank due to his hook and stun.Playing as ezreal,you will want your creep score to be really high,dat also depend's on your support,if soraka you can spam your Q on minions,if someother support,just try to cs with patient and skill that you will learn over time.

At level 6,you will want to be a bully with ez,just poke with Q until they are low,and then just jump in with E and hit them with R,it will be a sure kill depending on your skill.SOmetimes early you should flash with E and poke with Q for the extra E damage,but you should watch out for your mana too!in team fight's position yourself at the back of the fight and autoattack the enemy carry if near,your role is to give the enemy all the damage you have,so just stay back and poke with Q and ult when you see a change for a kill or getting enemy's lower.Note:You should use your ultimate to farm minions so you could get better items.