Hi Apurupa Konathala,
You can use the widget https://marketplace.mendix.com/link/component/111485
There is no way to disable past dates in the Calendar widget. You can look for a widget in the Appstore that has that possibility.
However you can use Validation to stop user from proceeding until the field is valid. In the default widget propertie in Validation, select Date in Future or add custom Validation as :
$value != empty and $value >= [%CurrentDateTime%]
Or you can also call a microflow onclick of Save button and check for this validation in the decision box before committing.