HI @Anonymous ,
Could you please share a bit more about your scenario?
Do you want to set a Default value for the Date field and Dropdown field in the Edit form of your app?
Currently, the Default property of the fields in a SP list would not be applied to a canvas app. If you would like the Default value of the fields you set within your SP list could be displayed well in your canvas app or custom form, I afraid that there is no way to achieve your needs in PowerApps currently.
As an alternative solution, you could set the Default value for corresponding fields in the Edit form of your app directly. I have made a test on my side, please take a try with the following workaround:

Set the DefaultDate property of the DatePicker control within the Due Date Data card to following:
If(SharePointForm1.Mode = FormMode.New, Now(), Parent.Default)
Set the DefaultSelectedItems property of the Combo Box within the Status Data card to following:
If(
SharePointForm1.Mode = FormMode.New,
{
Value: "Pending"
},
Parent.Default
)
Note: The Status column is a Choice type column on my SP List.
Please also check and see if the following blog would help in your scenario:
https://powerapps.microsoft.com/en-us/blog/default-values-for-complex-sharepoint-types/
Best regards,