The first month is always included. Add another full month when the landlord asks for the last month up front. The deposit is the rent multiplied by the number of months the deposit represents. One month of deposit on $2,000 is $2,000. With first and last, the total is $6,000.
A pet fee, a broker fee, or a utility deposit is a dollar amount this page does not have a field for. Add it after the total. A deposit of half a month is 0.5 in the deposit field.