best 5 starting legends for beginners?

Master Yi, Jinx, Miss Fortune, Ashe, Teemo and Garen.
All of these are best for starters. You just have to settle with one or two that suits your gameplay. Yi can be extremely vicious if you keep him alive and keep building it. Last hitting an enemy who is trying to escape or creep using alpha strike (alpha strike, if used properly and with timing, will land you far away from the enemy hero saving you and making you stronger with every creep/hero kill.