I have no experience with playing a pally, so i will just tell you the shaman side.
If you want to do damage, go with elemental for ranged dps, or enhance for melee dps. Both do very well in dps meters and are fun to lvl with. I prefer the enhance, especially for lvling, but its really a ranged/melee preference for you.
As far as weapons go, for enhance use DW and get either axes or maces, you are looking for +stam, +strength, +attack power, +agil, +hit
For elemental, use a 1h axe or mace and a sheild (though dont quote me on this as i have never played elemental, read the sticky for more info)
For race, it depends on what you want. Orcs have get an expertise bonus to axes, trolls regenerate health faster, and tauren get war stomp. All good things but its just a personal preference.
In a group, you will be dps. at low levels you should be fine healing as well if you know what you are doing. But since you mentioned you want to do damage-->you are dps in a group.