Abdoreem,
Odoo is such a great framework where the existing modules are a great teacher for you.
If you want to have a warning on write, you can plan to add a constraint and that constraint upon failure, can show such a message. See the example in addons/product/models/product.py Line 40 onwards.
If you want to translate that message, you have to make sure to use _ in the message provided that you import the _ class. Afterwards, make a .po file Or use Odoo utility to export translations and import it back after corrections.
Thanks.
a warning in CORE odoo module so i cant fined the main class to inherit it ...