Power Apps set(var for DateAdd is blank

Question

I am new to PowerApps and am trying to follow a Calendar build. I am trying to set a variable for a date that populates the first Sunday of the month.

Set (varVideoMonth, DateValue(Month (Today()) & "/" & "'¡" & "/" & Year (Today()))); Set (varVideoFirstDayView, DateAdd(varfirstDayMonth, - Weekday(varVideoMonth), Days));

This is the code that returns varVideoFirstDayView = Blank.

the other (varVideoMonth) returns the date properly. I am not sure what I am doing wrong. Any suggestions would be helpful. Thank you