What class are you?
For most classes 12 UMD at Lvl 13 1st Life isn't bad.
Because UMD gear is few and far between and UMD Tomes are separate from standard skill tomes {you have to actually buy them separately}.
UMD is a Class Skill for maybe 4 classes - Warlock, Bard, Rogue and Artificer - This means any other class that doesn't have at least one level of one of these is stuck at a maximum of 2 at 1st level and 1 for each subsequent level or at lvl 12 - 13.
There is the http://ddowiki.com/page/Golden_Cartouche which can be got from the end reward list of Delera's Tomb Chain which can give you +3 to UMD.
There is some random UMD gear that I think would generally give +2 at your level which won't stack with the aforementioned named item.
And
You can use Heroism Pots or Greater Heroism Pots/Scrolls to get your UMD up by another 2-4 points.
You should also invest in a +6 - +8 Charisma item for another 3-4 UMD if you haven't already.
So....
Base Skill 13
Charisma Dumped at 8 and a +6 Cha item = 14 or +2 {16 Cha is +3, 18 +4 and so on}.
A +2-3 item
And you should be able to get to 17-20 UMD
Add a Heroism Pot and your UMD goes up to 19-22
Add a GH Pot/Scroll and your UMD is between 21 and 24.
Tomes will push this up further but I wouldn't be looking to buy UMD tomes until I'd bought quite a lot else for this game.