Hopefully these 3 things

I don't know if anyone can do this for me because i'm a beginner in which Craft. I would prefer a another female to the spell casting it has to be temporary and my fiance has to be able to change back into a man by sunrise or whenever he wants and no one can see him as a female and a mermaid at other times not even me. I've talked to him and asked if he would do this wish for me. He said yes. Since he's a big Wrestling fan he said for transforming into a woman he would like to look head to to exactly like Becky Lynch and then For the Mermaid keep the Red Hair color and make the part the covers her C cup breast and her Tail Hawaiian Islands them's Since we were there and got engaged. Hes all in for this. And he wants it to last a month if it has to be longer that's fine as well. Also for me I would like a spell cast on me that makes my sex drive stronger a longer. My name is Clara and His name is Chris But On here i'm Rikki and my email I'm Cleo. If it can be done on the full moon that would probably be the best if it can't be done that's fine as well. Thanks

I'm sorry, but spells don't work like that. It's impossible to change into a mermaid, change into female, change your hair color etc. This is not how magick works. Magick works by working with energy around us. As for your question about increasing sex drive, there are plenty of aphrodisiacs you could use. If you use some herbs with those properties and make them into a tea, you could charge the tea with your intention. But be aware, magick does not make huge and dramatic changes instantly.

How would that work then. and how do we go about doing something like that with the energy etc.

It is outright impossible to do the things you are asking for, with or without a spell. The only thing that is reasonable is in increasing the sex drive. I would look into mundane (non-magical) approaches to that first though, and then look into spells for it.