Hi Vignesh,
Go to your module there is option called domain model where you can able to create the entity along with attributes which you want.
Pls find the below images.
Hi VIGNESH R,
Please refer the below link. It has the entity creation and adding the attribute and the type of attribute.
https://docs.mendix.com/refguide/entities/
https://docs.mendix.com/refguide/attributes/