This time last year I was in a similar position to you, I knew I wanted to build model (RC) model boats but I really did not know what type. My approach was to read dedicated magazines, Model Boats and Marine Modelling International, use the www for research and visit as many shows as I could, to find out what type of model attracted me. I also knew that I had no boat modelling experience whatsoever so I decided that I would not be too ambitious with my first boat/ship, i.e. not a complex 1:12 scale Lifeboat or highly detailed warship, but one that I could comfortably complete and enjoy and not one that I lost interest in half way through because I was out of my depth (no pun intended!). I must admit that this has been a past weakness of mine with several "hobbies/interests" discarded as a result.
The outcome was that I chose a "beginners" kit that I not only enjoyed building, in a reasonable time, but one that also enabled me to begin to gain a set of skills which I could transfer to more complex models at a later date. The model is also great fun to sail, which I manage to do fairly regularly, at a local club, which I joined during the build. I recommend that you join a club if you can.
Having gained confidence and some experience with my first build I am now being a little more adventurous with my second model and have chosen a semi-kit with which I am able to do a fair amount of scratchbuilding using detailed plans. Of course the big advantage is that I now have a model which I can enjoy sailing whilst building the second in between- the best of both worlds.
I realise that your own position will be different from mine but I do advise you to take some time to do some research, it really does pay off.