Until Lv46 for Total Eclipse, don't bother doing high damage on packs as a Paladin. Your AOE damage is non-existent to that point, so stick to Shield Oath for packs and use Sword Oath preferably for bosses after you established initial aggro (1-2x full enmity combo in shield oath). About cooldown management, don't worry too much now. Until Lv40+ where you get more cross-role slots and Bulwark + Sentinel, you basically only have Rampart to use. Anticipation is fine, but early-on you may want to help them on AOE pulls by activating Convalescence to boost heals - particularly good if your Healer is not exactly the master of his craft.

Regarding gear, even vendor gear is fine as long as you STRICTLY stick to what is actual tank gear (labels: GLA PLD MRD WAR DRK, if it has LNC DRG it is NOT tank gear) and keep it updated pre-50. After 50 you have many options for gear and you get some along the way as well.