The latest server version is MC 1.1
You are probably using Tekkit latest build (1.2.5)
1.1 Is not 1.2.5, go into settings then press the circle named: Always use recommended builds.
I know you are a noob, and the admins are not reeeallly HELPFUL but when people like this shows up, i can understand why, go read a wiki. Or look at other threads before starting a new one. Just one note, if you are messing with too many settings, anywhere, a gorilla will come from the moon and shit in your pc.