Below are my suggestions :
1. Find out more your dream careers. Sometimes, there may difference between the reality and what you have in your mind
2. Speak to someone who are working in these careers.
3. Find out the entry criteria of the relevant subjects in the college
4. Attend information session of the relevant subjects held by the college. Speak to the professors if you can
5. Explore any intern opportunities working in the industry
Hope this helps! Good Luck!