Hug the turret and try farming mobs. Because "Ezreal" is too squishy in the beginning. When you get ultimate try to help our team "gank".

Solo is pretty easy as Ezreal, because all of your abilities are range, "CD" is fast enough.

Use "Essence flux" it makes you enemies attacks too slow, then use "Mystic shot" it makes faster "CD" and. Repeat those attacks and always try to move, if your target is running away use "Arcane shift" (it's similar skill to flash). Ezreal is very squishy champion, so buy items with "HP".

Stay behind the tank, try to strike with ultimate.