How to make a plan for our life

You asked some suggestions about your young brother's later career. I do think it is a good idea to introduce your young brother some info and knowledge about the current major and let him come to realize what he could do when he grow up. However, I think this process he comes to be aware of what he could do will be very long, because he can’t understand some of the info according to what he has known at present, which will lead to what he learn from the info you given is just some superficial points. Anyway, it is very kind of you as a big sister to introduce him these info and I think it will be beneficial for his later development.
When we consider our career, we should consider our interests and how to maintain our life or earn a nice living with it. In the developed country, the youths consider more about their interests. Yet, for us in China, a fast developing and transforming country, we chose our career or job according to the market generally. Sometimes we may feel disappointed about it, but it is the fact. Maybe when you brother grows up, the situation will change, but I am not sure at present.
Sometimes I could still remember my dreams when I was young; and these dreams were fading and new dreams came out with the fleeting time. I was wondering why I changed my dream and why I came to where I am now. Maybe it is partly because I did not get enough info about the future. Maybe it is party because you will be end in loving something even though you are forced to do it at first. Whatever, it seems I am doing something interesting.
I would like to introduce your brother about robot first. This field is very interesting to most people and you could also find a relative nice job in the present job market. So what does this field do? Generally speaking, we need robots to complete the dangerous work or do the job effectively. In order to make a robot, we need to complete the below work. First, theoretical design: chose a theory how the robot works, arrange the trajectory of the movement of the robot and so on; second, the conception design, chose concrete structure, controller and control algorithm for the robot, and so on; third, detailed design and manufacture of the robot: draw the engineering drawings and figure out how to manufacture the parts of robot; finally, assembling and adjusting the robot, in this step, we should continue to modify the program and structure to make the robot fulfill the function we need.
We can see robotic tech is an interdisciplinary subject which involves various disciplines, such as mechanics, automation, material science, computer science, artificial intelligence and so on. But if you want to learn it, you’d better choose automation or mechanics as your undergraduate major, because they are the basic fields. Furthermore, I think automation is the best. In order to do well on automation, you should be good at math and physics. However, you should not worry about it; you could do very well if you spend enough time in learning it in university. I am not going do give you more detail about automation, but I should remind you that even if you don’t plan to do further research on robot, you will find you have a wide choices after graduation with a major of automation.
The other majors I recommend are info tech (IT), computer science, economics, and accountancy. These fields, I believe, will continue to be very hot in the future that we could see. Personally, I think these fields are kind of interesting, partly because you could find a good job with it if you do excellent on it.
Ok, that is all. If you don’t think I answer your question properly or completely, you could write back to explain it and I will be glad I could help and provide you more info. I find some materials from the internet and if your young brother reads these materials and find interests in some fields, you could tell me or the others who is familiar with that field and we could provide him more concrete info about that subject.