L1 -- for middle schoolers or those wanting a no-nonsense type of software-writing resource for those only concerned about functionality.
L2 -- we recommend for everyone to at least try to follow this path. The computer science maturity gained will be very valuable for learning really any other concept/programming language. Moreover, in this path, you will learn how to design custom correctional code and controllers for significantly more accurate movements (both in autonomous and user control).
L3 -- we recommend this path for those truly eager to obtain the greatest competitive advantage they can through software. However, be cautious: some of the more advanced topics may be dense or intimidating and will require a good deal of time to learn and internalize.