Please check below example to get output variable value by executing a stored procedure.
DECLARE @return_value int,
@Ouput1 int,
@Ouput2 int,
@Ouput3 int
EXEC @return_value = 'Your Sp Name'
@Param1 = value1,
@Ouput1 = @Ouput1 OUTPUT,
@Ouput2 = @Ouput2 OUTPUT,
@Ouput3 = @Ouput3 OUTPUT
SELECT @Ouput1 as N'@Ouput1',
@Ouput2 as N'@Ouput2',
@Ouput3 as N'@Ouput3'