Re: Help building a flow using Today's Date and other Date field
Hopefully this is what you're looking for. Note that you'll need to change the field names to match what you have in your table.
For this example, I'm using the following Dataverse Table called Assignments. Note that Albert doesn't have a Completion Date filled in, and Jane's Start Date isn't one year ago, so the only record that should be updated in Grant.

See full flow below. I'll go into each of the actions.

Recurrence is set to run daily.

List rows retrieves the rows where the Completion Date is filled in, and the Start Date is equal to the Date 365 days ago. Because this will only return the rows we need to update, we don't need a condition within our Apply to each.
//You'll need to change the field names to match what you have
cra85_completiondate ne null and cra85_startdate ge '@{startOfDay(addDays(utcNow(), -365))}' and cra85_startdate lt '@{startOfDay(addDays(utcNow(), -364))}'

Apply to each iterates over each of the rows returned from List rows and uses Update a row to update the Status Reason to Earned.

After running the flow, we should see the following:

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