If you retrieve Dataverse data

Getting the formatted value of a picklist, lookup, date or number field, use an expression and add @OData.Community.Display.V1.FormattedValue after the field name like this:

outputs('Get_opportunity')?['body/my_somepicklist@OData.Community.Display.V1.FormattedValue']
or
outputs('Get_opportunity')?['body/_parentcustomerid_value@OData.Community.Display.V1.FormattedValue']

For gettting current date, use an expression like this:

utcNow()

For formatting values, use an expression like this:

// formatting number with 2 decimals in Dutch notation:
formatNumber(outputs('Get_opportunity')?['body/my_somenumber']), 'N2', 'nl-NL')
// or formatting number with 2 decimals in Dutch notation with Euro currency:
formatNumber(outputs('Get_opportunity')?['body/my_somenumber']), 'C2', 'nl-NL')
// or extracting the year from a utc date in West European timezone
// (almost all dates in Dataverse are utc):
formatDateTime(convertFromUtc(outputs('Get_opportunity')?['body/my_somedate'], 'W. Europe Standard Time'), 'yyyy')