Marko, the lens you have purchased is a really good lens. If you take some pictures with it and you are happy with the results, then it is a really, really good lens for you.
As to whether you should have a UV filter as a protection for the front glass element, only you can really answer that.
However, think about a few scenarios you may encounter with the lens on the camera.
You may be walking around a crowded market with the camera hanging from it's strap near your waist, someone with a hard object, like a box, may just accidently hit the lens element.
You may be near the sea one day, salt laden air with the misty clouds common to this environment, surely isn't too flash for the front element.
Personally, I always have a UV filter on the front, unless I'm running an orange or like filter for my B&W film. The other thing I find good to protect my front element, is a metal lens hood, not the folding rubberised type.
In fact one of the better things you can have on the end of your lens is a correct lens hood. The lens hood will reduce possible flare from extra light as much as possible. Also a hood will be really beneficial for keeping light misty rain off the front element, something which may apply to you where you live, I would assume.
As your ability to purchase lenses and/or photographic equipment as time goes by gets better, you will become more able to figure out which direction you will head to. I think the 28mm lens is a very good semi wide lens, with great possibilities.
The fact that you have a guarantee, for someone in your position, is a bonus, and something not to be sneezed at.
I wish you well with it and look forward to seeing the fruits of your exposures!
Mick.