how can i be sure?

I did a mermaid spell. The one with insouciant inclemency
How will i determine if it worked? When will the symptoms appear? There is a lot of spells with the chant "insouciant inclemency"
Im so confused what to follow. So i did the one that i first saw. Should it be full moon? Or night? Can i do the spell on day light?
Please answer me! Im dying to be a mermaid!

It will not work because it is not possible. Thus you will experience no symptoms or side-effects from doing that fantasy spell. You are a human, not a mermaid.