Go to your professor and engineering advisor with questions.
Who says you need to build stuff anyway? You as an engineer need to solve problems even in mechanical. You are part of a team. You have to design efficient systems. Depending on what part of mechanical most aren’t physically building anything if this makes sense.
In your classes and labs you will come across different ways to build things. Some might be better with hand tools and you might be better with a CAD system. As a first semester engineering student your basically taking basic courses. Enjoy those. Engineering hasn’t really even started yet.
Again your professors and advisors can help you understand all of this.