If you are thinking about getting in IT field then this is the time to start to plan. A word of advice: in IT field specialisations are looked for, for e.g, are you an specialist in web technology or database management or operating systems.
But in courses such as BCA, you will be exposed to a gamut of technologies. From this you should choose something that you like and would prefer working on. Something that suits your temperament and station in life.
If you like drawing and are into short programming, then choose web development. But if you are a detailed person, programming for operating systems would be your thing. If you are an investigative type – hacking and protection from hacking would be what you may do best.
When you do decide to follow one kind of specialisation, there are a variety of programming languages and frameworks that you have to learn to get a mastery in that specialisation. You should also get some experience in real life coding BEFORE you graduate. For that, you have to start early.
Thinking on those lines, there are gamut of basic courses you could start learning even before you have joined college. You can choose to have basics courses in C, C++, C#, Java, HTML, PHP, Webdesign, Photoshop etc.
Do not think much before joining one course, if you don’t like it you can always change it after two months. But choose what specialisation to pursue carefully, you career depends on it.
Your target should be that by 2nd year of your BCA, BSc IT or B.Tech you have enough skills to be a able to get jobs doing contract work, either independently from some contacts or in sites like Elance or in a small company.