GCSE ICT or CNAT Creative iMedia?Watch
ICT is a more 'general' subject and will focus on a broad range of topics. From that, you can progress on to many different areas within IT at college and then on to university if you so choose. This GCSE will allow to explore what it is that really interests you and will focus on more specifically what area you want to go down (such as; programming, web design, network engineering etc.)
I will admit that I have no knowledge of CNAT Creative iMedia, however, read into it to see what it is all about and if it is something that you would enjoy doing and might use in your future career.
What is importnat to remember is that these early steps form a base for future study. You need to make sure that whatever you do, you do it to the highest standard that you can. If you do, it will make things so much easier down the line as if you don't put the effort in, it could cost you in time and effort to put right.