Have an Answer?
I've thought a long time about being an engineer back in college. I didn't end up becoming one (for a lot of my own reasons), but all that time I spent thinking about it has allowed me to go from having little understanding of engineering to understanding all the varieties it comes in.
In general, an engineer is someone who takes what has already been discovered in academic research and produces something useful with those research results. This is the distinction between being a scientist (who purely does research to discover new things) and an engineer (who takes those research results and thinks about how to create useful products).
Therefore, just as there are many types of scientists, there are also many types of engineers.
One can become a biological engineer. For instance, biological scientists discover a pathway for how HIV infects the body; biological engineers take that knowledge and can create (engineer) proteins synthetically to block that infection pathway.
There are also mechanical engineers. They use their knowledge of physics to create products such as: prosthetics that would properly support human weight, the axles of cars, and other products that would require you to think about balancing forces (broadly speaking).
There are material science engineers. They study the properties of different types of materials and think about what types of materials different products should be made out of. They help determine what materials our clothes, computers, machine parts, sports wear, should be made from.
Then there are computer scientists/software engineers. They write computer code to create iPhone apps, GPS systems, and any other systems that automate processes. Lots of them work at Google, Facebook, TripAdviser, Yelp, ect., to name a few.
And we have chemical engineers. I don't know much about them, but some chemical engineers work in the oil refinery industry; they create chemical processes to change raw chemicals (i.e., crude oil) to something that people can use (i.e. gasoline). Of course, they don't all work in the oil industry.
Then there are aero/astro engineers. They build planes and space crafts.
And the last main category I can think of: civil engineers - they build bridges and buildings. They're the people we classically think of as engineers.
There are also some other categories I won't go into detail here (electrical engineers, hardware engineers, computer network engineers, and others).
So you'd want to narrow your interests first. But whatever you choose, you need to have a solid background in math and need to have the motivation to work long hours in school. You should start your engineering degree during your sophomore year of college, and hopefully your school has a list of the required classes you would take. During the summers, it would be a good idea to find some engineering internships to help you figure out if this is something you would enjoy doing.
It all depends on which field of engineering is interesting to you. I recommend that you look at a list of engineering branches and descriptions, find what sounds interesting and exciting, and then start your research.
You can start here: