So what do you want? A magicka based DPS build or a stamina based DPS build ?

Stamina templars have higher dps in general, but if you have an altmer templar, i would recomend you to go with magicka build... just to take good advantage of your racial passives.

Templar is veeeery easy to play if you do it right.

Against mobs: Throw a blazing spear at the mobs, then walk straight in and spam Puncturing Sweep. It heals you for 40% of the damage you do, so you get to love rushing into 3-12 mobs at the same time, the higher the number - the more your healthbar stays at 100% and you can block-cast it. The spear will do additional damage and stun 1 enemy to begin with, so it is nice. << It also works well for soloing bosses and dolmens.

Radiant Destruction - morph it to Radiant Opression, and use it against single target enemies, when they are down in health. It is a great execution skill.

Get a destro staff, get the skills: Crushing Shock (morph of Force Shock), Elemental Drain (morph of Weakness to Elements), Elemental Ring (Morph of Impulse).
-Crushing shock is good against single target enemies, in case you do not wish to go into melee range of them, and you can easily weave with it. The other morph Force Pulse does not provide cc but gives higher damage.
-Elemental Drain is good, if you solo a lot of bosses, it lets you do additional damage with crushing shock.
-Elemental Ring is an alternative to blazing spear + puncturing sweep spamming. I sometimes cast blazing spear and rush into the mobs and use Elemental Ring, however puncturing sweep is better for survival.

For your build: since you're low level veteran, just go with a full set of Seducer and 3 pieces of Torugs Pact - alternatively wear a full set of Seducer and a full set of Warlock.
- Seducer and Torugs Pact are craftable, Warlock is not.

Since you're a templar, put all your attributes into magicka, slot Structured Entrophy on both weapon bars to raise your max health with 8%. Choose a campaign in cyrodiil that is dominated by your allience to get emperorship buffs. If things go very bad and you need extra health, use 10 attribute points in it or just slot a shield skill.

Slot Breath of Life on at least one of your bars as a "oh poop I am so doomed" situations.