Hi Davide, Welcome to EasyEDA. Please see: https://easyeda.com/andyfierman/Welcome_to_EasyEDA-31e1288f882e49e582699b8eb7fe9b1f

Hi https://easyeda.com/Doc/Tutorial/Introduction.htm#Design-Flow-by-Using-EasyEDA https://easyeda.com/Doc/Tutorial/Schematic.htm#Search-symbols https://easyeda.com/Doc/Tutorial/Schematic.htm#Find-Components-In-The-Schematic https://easyeda.com/Doc/Tutorial/Schematic.htm#Placing-Components https://easyeda.com/Doc/Tutorial/Schematic.htm#Rotating-the-Prefix-and-Value-Name-of-components https://easyeda.com/Doc/Tutorial/Schematic.htm#Adjusting-Components

This will also help: https://easyeda.com/andyfierman/Elements_of_a_simple_PCB-e42c7b2a4e17449f821a97d04806aeeb

@Cristinana, I did not understand that you were asking about PCB Assembly (PCBA) and not about how to place components in a PCB layout. PCBA is coming to EasyEDA soon.