Where do I enter personal days on vacation rental

Work through the property in the assets/depreciation section of the SCH E and one of the screens will ask you for days rented. Make sure you select the option to indicate you had personal use days. Otherwise, you won't be asked for that.

Take note that personal use days is days you lived in the property "while it was classified as a rental".  What you did with the property before it was converted to a rental don't count for anything.

Yes, the screen looks like this -

I got there by going to the "Rental Properties and Royalties" section

Click UPDATE

Continue to the "Rental and Royalty Summary" screen and select EDIT for the property

Select Update (or Start) for "Property Profile"

First screen reports the address, second is Type, Third asks if it was sold or converted, 

The Fourth screen asks "Was This Property Rented All of 2022?" Select NO and the number of days. 

@Bill C2