welcome!
You should be able to keep a pair of clowns ,an anemone, and a goby/shrimp pair in an 40 gallon tank. As others have mentioned just do your research as to which species are best suited to each other and go very slow when adding each new member to your aquarium. Even once your cycle is complete adding more biological load to the system needs to be followed by an adjustment period before adding more load once again.
If you do this you should be fine
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Biocube 29 est 05/05/08, Koralia 1, 30lbs live rock, ,yellow tail blue damsel, pair cinnamon clowns, baby snowflake eel,Toadstool , metallic green mushroom, assorted zoos , kenya treen
180gall display, 190 pds live rock, virgate rabbitfish,bluejaw trigger, bubblletip anemone,yellow tang, sailfin tang,melanarus wrasse, cloud wrasse,

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