<p>No one can really answer your question. By definition in all branches of engineering one can design new things, etc. The different branches are so disparate that you really need to investigate each one a bit to see what might excite you more than another. By this I mean that many people would get excited by EE but not ME or vice versa, CS but not EE or vice versa, civil but not CS or vice versa.</p>
<p>Regarding the ‘not sititng at a desk’ - you’ll probably need to get over some of that since in virtually all branches of engineering if you’re doing design and development you’ll likely spend a lot of time in front of your computer. This isn’t as bad as it sounds though since you’ll probably be so absorbed in what you’re doing it doesn’t matter so much that you’re in front of the computer as opposed to the old days of sitting at a drafting table or otherwise drawing up your designs whether it be mechanical, electrical, civil, computer science, or other branches. Depending on what you do you may also spend some time in some labs (ex: prototyping your new circuit design or mechanical chassis), will likely spend time in meetings, and may travel somewhat.</p>
<p>Use an example - like a UAV (unmanned aerial vehicle) - would you be more interested in designing the structure of it, the electrical circuits in the avionics, or writing the software that’s the brains of it that allows it to fly unmanned? You can come up with thousands of other examples (a car, a television, a huge building, etc.).</p>
<p>Think back to your physics class for more of an idea.</p>
<p>If you research it and still don’t know then in your first year make sure you take an EE course, a CS course, a MechE course, physics, etc. You’ll likely need to take most of these in your first year anyway.</p>