1. Been ages since I leveled but BnT rend, thunderclap, cleave for aoe and shieldslam devastate HS for single target should cover it once you get to lvl 68ish I think have fun with shockwave.
2. Get tidyplates threatplates and omen to watch threat. For the rest its just personal preference but I like bartender and a unitframe addon like pitbull.
3. Look at guildox or wowprogress for a guild on your server at your level of progression and see if they need a tank, this is once you're 85. Sometimes guilds also abuse tradechat for promotion or you can look at recruitement part of tankspot or mmo-champion.