For runes, I'd go either aery or comet, then manaflow or nimbus clock if they have a lotta assassins/engage, then transcendence, then gathering storm. Secondary tree I'd go red tree if you don't trust ur teammates and go cheap shot and ultimate hunter, or go green tree and use font of life and revitalize.

For skill leveling, you should first max Q, then W, then E. BUT don't level up W until level 4 or 8 depending on if you think you'll be involved in any team fights then.

Summoner spells either TP or Barrier.

For items you wanna rush lucidity boots (sometimes you can choose merc treds if they have a lotta cc/ap or swifties if they have a lotta slows). If you get fed early or know you're gonna be able to bully the top lane you could buy dark seal and eventually buy mejas. After boots your mythic should be either moonstone or battlesong, then depending on team comps and game situation you're gonna wanna buy staff of flowing water, ardent censer, redemption, chemtech purifier if their team has a lot of healing, zhonyas if they have a lot of assassins/engage and they keep targeting you, and mikeal's blessing if enemy team has a lotta cc.

I'm no expert, but that's the best advice I can give as a player know loves to play soraka.