Hey Pedro!
I’m sorry for the delay in response. I unfortunately don’t have 74HC595 at hand, so I was hoping somebody who has one was gonna respond.
I’m sure you saw this past forum post, but just in case, here it is: GPIO outputs and 74HC595 Serial Latch by example, beginners guide
Were you able to get this example running?
We also have an active Discord where people are asking and answering each other’s hardware questions 
Please feel free to join and ask about 595 on the ‘hardware’ channel.