Fabio,
Ciao. I wish it were that simple. I've been in photography for a very long time. I don't do wet plate photography, nor any sort of plate photography. However, from what I know about plate photography, I would suggest that you find someone that is accomplished in this and ask if you can take lessons from them. It's not the simplest thing in the world, and you could spend a lot of money and time trying to figure it out yourself without ever getting anywhere. Like the age old apprenticeship programs that all sorts of artists are familiar with (I had to do this for intaglio etching and fresco painting), it would be invaluable (and save you a lot of that money and time) if you got someone that was good at this to teach you the process. Some of the chemicals are acidic, hazardous to breathe (as in cyanide gas), and/or potentially explosive. It's nothing like conventional film photography.