Question: I am in 10th grade and I think I want to go into engineering. But there are so many different areas of engineering, and some of their names seem similar yet different. How do I decide which is best for me? What if I pick a major and then don't like it?
Your question evokes one of education's "chicken and egg" conundrums. You don't want to commit to an academic field before you understand it, but--in order to understand it--you have to commit to it. Confusing, eh?
Luckily, many college engineering programs offer you the chance to take a broad range of courses before deciding where you want your focus to be. But, admittedly, the terminology can be confusing.
You may find some help from the American Society for Engineering Education. You can find a lot of helpful information and publications geared to teenagers here: http://www.engineering-goforit.com/
Also, if it's possible for you to do an engineering summer program next summer, this can give you a chance to test the waters and learn more about engineering specialties before you start applying to colleges. There are many summer engineering programs. Often they are held on college campuses, although you may find day programs in your own community or nearby, as well.
Here are some links to help jump-start your search: (Some programs for next summer and their schedules may not be listed until winter or even early spring, but this will give you an idea of what to expect and where to look.)
If you Google "Summer programs+high school+engineering" you'll get dozens of other ideas, too.
Once you have a chance to try out different engineering fields, you may get a better sense of which is the best fit for you.