CP2K is an open source electronic structure and molecular dynamics software package to perform atomistic simulations of solid-state, liquid, molecular, and biological systems. It is especially aimed at massively parallel and linear-scaling electronic structure methods and state-of-the-art ab initio molecular dynamics simulations. Excellent performance for electronic structure calculations is achieved using novel algorithms implemented for modern high-performance computing systems. This review revisits the main capabilities of CP2K to perform efficient and accurate electronic structure simulations. The emphasis is put on density functional theory and multiple post–Hartree–Fock methods using the Gaussian and plane wave approach and its augmented all-electron extension.
I recommend reading through their latest paper for an overview of CP2K's design, including strengths and weaknesses. One thing to note is that, unlike VASP, CP2K's DFT module (QuickStep) uses Gaussian + Augmented plane wave basis sets, rather than simply plane waves. This has both advantages and disadvantages; while it makes the code run efficiently, it introduces the problem of choosing an appropriate Gaussian basis set for your application. Sometimes the ideal Gaussian basis set just doesn't exist for your system of interest!
I have used CP2K in my research, and my experience is that while the software is extremely powerful and efficient, the documentation is lacking for many of the advanced or highly-specialized features. Even some of the more basic features sometimes have very terse descriptions in the documentation. However, you can usually find complete explanations in the scientific literature, and the documentation problem seems to be getting better over time.
An installation Guide can be found here. To start out, I recommend going through the exercises given here. Once you get going, you'll be referring often to the reference manual.
Thankfully, when it comes to the molecular dynamics of the situation, ab initio MD as implemented in CP2K (Born-Oppenheimer MD) works essentially the same as classical MD. The difference is really just in the force field, which is calculated on-the-fly via density functional theory methods.