I want to implement a Basic Search function to my Django Project

I have a dropdown field with all model Fields of my userdb model.

forms.py

class searchForm(forms.Modelform):
    field=forms.ModelChoiceField(queryset=[f.name for f in MyModel._meta.get_fields()],widget=forms.Select(attrs={'class':'form-select','data-live-search':'true'}))
    class Meta:
        model=userdb
        fields='__all__'
        input=forms.CharField()

How can I validate if the input of the input charfield is correctly Formated depending on the selected field in field.