A lot of people have trouble with the swimming, so you won't be alone there. Most that I've seen that are "sprint" distance seem to be 1/3-1/2 mile, or 500-800 meters, and there is a "supersprint" distance that is significantly shorter.

You will want to build up your endurance to swim the distance comfortably, so I would spend time in the pool consistently to improve your comfort in the water. For the first time, your technique may not matter, but taking a class or being coached may really help you feel more confident.

You've got plenty of time to train. I say go for it Set your goals now and train for them. There are some books out there that can give you help with training plans for different distances, and you might check some of them out.