Take a look at the guild recruitment forum, you can probably find a newer guild that will be supportive of someone who is new to the bracket. If you are US, I would recommend against Bleeding Hollow and maybe Elune, as AGM would be a bitch to get there.
Hunter, paladin, priest, rogue, and mage are considered the 'OP' classes, to varying degrees.
Prot is the weakest paladin spec - you will be better off as holy for FCing and obviously healing, and ret for dps.
Thanks a lot!, I'm EU so do you know any good horde guilds?