Hi everyone,
Clownfish will die in freshwater and julie cories will die in saltwater. I've heard of guppies being kept in saltwater but I wouldn't dare risk it. If you have enough money you could get another tank or sell the cories and guppies and change from fresh to salt properly.
Just a note on your comunity;
I reccomend getting another couple of julie cories, your tank will probobly fit in because my my calculations you're only 53% stocked.