Use:  I needed a power automation to create a new column after a certain date and the update the sharepoint item in the new column with values from two other columns.
IE: Our testing closes May 10 and I need to record the users that registered for current years test so we could see it next year.  The column that stores the current data is called "CurrentSchoolYR" so we can continue to use it in the future.
The archive column that will be created when the school year ends will be called assignments2026.

Choices([@'Your list name'].SharePoint_column)

Example:

Choices([@'StateTestingProctor-Teachers'].TestSeason)

In a text label
Concatenate("Total: " & CountRows( YourGallery.AllItems ))

Concatenate("Your Label Text " & CountRows(Filter('SharepointList', YourColumnName = "Your text condition" )))

For example: 
The below script looks at a couple conditions and counts the items that fit the criteria. This script is placed in a Text Label.
Concatenate("Diplomas that will need to be mailed" & " Total: " & CountRows(Filter('2025SummerGradCeremony', StatusColor.Value = "Yellow" And DiplomaEarned.Value = "Yes" )))

What it looks like on the Power App

length(outputs('Get_items')?['body/value']) = 0

I needed to get the values of a custom "Attribute" field we had in Active Directory in Power Automate.

https://graph.microsoft.com/beta/users/USERS_EMAIL_ADDRESS?$select=onPremisesExtensionAttributes

In my PA, I used a compose action to dynamically change the user email address.

Here is the error in Power Automate:
Test connection failed. Details: Oracle: ORA-12504: TNS:listener was not given the SERVICE_NAME in CONNECT_DATA inner exception: Oracle: ORA-12504: TNS:listener was not given the SERVICE_NAME in CONNECT_DATA clientRequestId: 5d4ab5a5-d136-81dd-e0ab-ab62dd76e609

Here is what it should look like:

When this happens,

1. Save App, Exit App and Re-Start App.

OR

Patch(

SharepointList, ThisItem,

{

Reserved: true, ReservedBy:User().FullName,

ReserverEmail: User().Email,

LearnerFullName: If(IsBlank(tiLearnerName_3.Text), Blank(), tiLearnerName_3.Text),

WhoFilledOutFormText: ddWhoFilling_3.Selected.Value

}

);

So if the user doesn't select a date I have in the combobox, the gallery will display all the time slots Melinda has available.

Filter(TimeSlots,CounselorName.DisplayName = "Melinda", IsBlank(ComboBox2_1.Selected.DateDisplay) ||EventDate = ComboBox2_1.Selected.DateDisplay)