I want to create new entity with those fields
ID
Name
Description
doctrine will create the table from the Model Class, any idea how i can make the description translatable, I am new in shopware and i do not know how we can achieve this
Hey,
you have to define in your backend component the fields translateable with a translationType. All translations will be saved then in the table s_core_translations, so you can read all translations by type, your record id and shop. In the DI Container is also a service named „translation“ which helps you to read the translations in easy way 
Here is a good tutorial: https://salty.rocks/en/blog/shopwaremodelcontainer-using-translations