I would advise you to play some normal alone before you play ranked. Riot gives new accounts a unreasonable high elo at the start. This makes you play in games where you will get absolutely stomped by the enemy and as a bonus flamed by your mates.
Learn how to play the champ and position you want to play and have a look which items usually get bought and which masteries are used on this champ. If you have done this your experience will be much better.
Yone. Base Skin is so much better than other ones