SSD problem Macbook retina 12 - when I enter restore mode, the disk utility doesn't show me hard drive volume even if its IN the logic board of this macbook retina 12inch

Try this

1- Plug in Charger + USB-C cable to computer

2 - Power up computer and immediately press Command + Option + R

This is Internet Recovery mode. It will take some time to load depending on speed if Internet Connection

3- Use Disk Utility. Looks for View top left of Menu

4- Look for Apple SSD

5- Choose Apple SSD and reformat as Mac Extended HFS+

6- Once it finishes us First Aid to verify SSD

7- Exit Disk Utility

8- Choose Install New OS

9- this too will take some time as it has to download about 5.2 GB

10- If all goes well, it will install the most recent version of macOS available.

If this does not work, suggest you contact the person who sold you the MacBook and ask him to reinstall the OS

1 - turn off computer

2 - power up computer and immediately hold Command and R

See if it will boot in Recovery Mode

If yes, go to Reinstall macOS

For more details on the reinstallation process follow this link from Apple