hi just adding my 2cents worth

Try to gear up doing the normal instances as much as possible. Heroic bosses aren't that hard, but heroic trash can be a bummer.
We all know how hard Bog Lords hit

Heroic Instances that I did once i dinged 70: Slave Pens, Underbog, Mechanaar. However, my group often had an offhealer, like a spriest, elem shaman etc. to tide over certain hard trash pulls.

If you're really confident, try out the ones I mentioned. Do note that Mech and in parts of Botanica, a warlock makes it much, much easier.