Right now I'm a lvl 56 and it shows that there are no raids available for my level, so I was wondering at what lvl I'll be able to raid.

85. And then you will have to spend a lot of time at 85 getting gear to make sure you have a high enough gear score before you can raid as well. Tecnically there are level 60 raids level 70 raids and level 80 raids as well. But no one does them, because people only raid the max level content. Raiding is difficult, you will need to really know how to play your class or you will soon be kicked from the raid. Generally you will have to make friends while running heroics or find a guild to raid.

Level 58 is the minimum level to enter level 60 raids, but given that there are few left to even encounter that would be pointless. Raiding is generally only "productive" (if it can be called that) at the maximum level. This is usually true in any MMO. As such, your best course of action would be to wait until 85 to raid. If you don't want to, you could try to form raids for TBC instances such as Karazhan, SSC, Hyjal, etc. once you hit level 68, although 70 would be recommended.

wow is modinha