Are Tanks on Rift or WoW supposed to just have loads of life and hold aggro but not do as much damage as the others in the group?? New to tanking you see and wantted to know what are the main points of tanking and atm I have loads of life on Rift but don't have strong attacks.

Pretty much.
You make all the targets attack you so the healer only has to heal one person.
You keep your main damage dealers alive while you just keep all the mobs penned up.