General

Thanks, guys! I was a little worried on my damage because i didn't want to mess anything up on my beginner. But thanks again. :]

You improve it in the same way any job improves it's damage.
Attack and the main stat.
Beginners have around a 1.2x multiplier with any weapon so you should adjust accordingly. A familiar never hurt.

Want some easy ways to suddenly gain a few hundred points on your damage?
Make a Cygnus and level it. A 20~24 attack boost is nice to have.
Keep some Warrior Elixirs on hand--that's another 12 attack that can be bought whole-sale.
Attack WGs are getting cheaper these days due to end-game potential. It shouldn't be too hard to get a hold of one.

However, it's important to remember--No Mastery, no % skills. Damage is not your main goal here. You're not around to outdamage the next guy in line--you're here to have fun. Damage is only important to help you train easier. You're a beginner. Get used to it.

[quote=StormNormandy]If you're worried about damage on a Beginner, then maybe a Beginner isn't for you.[/quote]
This.

Even if you want to get a high range (for any sort of personal reasons), don't worry about buying anything until you reach higher levels and invest in end game equips.
You start to make more funding as you level as well. Just make sure you keep a semi-high leveled jobbie to help keep an inflow of mesos.