I will explain how to make the fish soup, in a basic manner.
ingredients : roux( 50/50melted butter and flour mixed together), it is important not to make to much of this you do not want to end up with a fish pudding.
Fish stock: you can buy the stuff you get at the store that you just mix with water, or if you have the time you could make your own stock, that is what I would recommend.
Lemon juice: just put in after taste, depending on how much you intend to make, the Lemon is supposed to complement the taste to overpower.
Cream: the amount of cream depends on the amount of stock, put in the cream until the soup gets that white creamy look, you would think that in a fish soup that the fish stock would be the most important ingredient, but in this one cream is equally if not more important.
White wine: just a little, to give it that little extra flavor.
Anise liquor: a few drops of Pernod or Sambuca or any anise liquor really changes the taste of this for the better.
Salt and pepper: only at the end and only if it needs it.
Dill, parsley, chives, leeks, carrots: all after what you like it will all go extremely well in here, just cut the up and put them in if you feel it needs it.
Fish and some shrimp: kinda stupid to mention but, a fish soup without fish is not really a fish soup now is it?
This is very simple, all you do is make the roux, then mix everything together, and let it cook for some minutes, and enjoy.