Thanks @Max Foerster - K15t
@Manuel Bastardo Castellano I agree with everything @Max Foerster - K15t has said. I took (and passed) the ACP-600 with the right amount of preparation it was challenging but not impossible to pass.
If you look at the exam topics list for the ACP-600 vs the ACP-100 you will see that the ACP-100 has many additional topics that are not covered in the ACP-600.
Personally, I felt that the ACP-600 was a nice way to focus on a smaller amount of knowledge so that I could undertand how the format of the exams would work so I would know how to prepare of future exams.
I hope that helps!
-James
@Manuel Bastardo Castellano I will suggest you go for ACP-600 first. It will set a foundation for ACP-100.