so i want play ranked but i don't want to look like a tard so befor i start i was thinking to maybe get 2 more rune page for suport and jungler and maybe learn those role befor jumping in there what you guys think ?

I ended up playing till about 500ish wins until I even touched ranked. The skill disparity between a level 29 and a level 30 actually incredibly huge. Just because one hits level 30 does not mean they should jump in ranked. If you blindly jump in now, your elo will suffer and its a hard brutal climb back up. Play a couple hundred more normals, find champions which you can get to know the mechanics of, make sure you know how to play every role somewhat reliably before you even touch ranked. Also, try to duo que with a friend when you can.

Yes, learn support and jungle, and have a runepage for all roles available. Have a few champs in each lane that you're good at, so you don't have to rage when your favorites get banned.

I think that before playing rank you should at least have a 200 win. Also a good understanding of the game and objectives and make sure you can fill any role with 2-3 champ. Stay positive and be ready for the worst.

Good advice so far.

Be proficient in at least four of the five roles, and be sure those four include support and jungle. Know how to play at least 3 champions well for each of those roles - more is better. Know how to play at least 5 champions well for your preferred roles, and be aware of their good and bad matchups. More is definitely better here.

Have a large selection of mastery pages so you can adapt to as many situations as possible.

Have at least four rune pages, one AD, one AP, one Jungle, and one Support. More is better here, too, as it gives you increased flexibility.

Have several hundred normal wins under your belt from draft normal games. This will give you the experience with the types of situations you will encounter in ranked play, from champion select, to laning, to midgame objective control, to endgame pushing and teamfighting. The more different situations you have experience with, the better you will be able to react to them in ranked.

Also, work on your communication. Work with your teammates in champion select to avoid conflict. Don't rage in games, and don't respond negatively to other players raging at you. Tensions get pretty high in ranked games, so be able to keep your cool. If you can't do that, don't play ranked, because a team fighting amongst themselves has already lost the game.