Education Requirments
For any job there are going to be requirments in education, as for being a mechanical engineer, those educational requirments are that you need a Bachelor of Science degree, which takes around 4-5 on average to achive. You also need a Masters degree if you are planning to do robotics, which is what I will also need for education. That usually takes 1-2 years to get.
Key Skills
Some key skills that are required to become a engineer are being skilled in the field of mathmatics, such as calculus. Other skills like having a extensive knowledge of physics and science are also needed to become a mechanicak engineer. And of course you'll need to be skilled in technical work as you need to be able to fix and create machines and mechanics as a mechanical engineer.
Licenses
If you want to apply for something you will most likely need to be licensed and trusted to do the objective, this goes the same for a mechanical engineer as if you want to apply for a position of being a professional mechanical engineer you will need 4+ years of experience and pass the Principle and Practice exam.