Moonlight Falls is one of the better EA worlds (IMO). Not laggy like Bridgeport, lots of room to grow (also unlike Bridgeport).
Elixirs to make sims into supernaturals should eventually show up at the Elixir Consignment Shop. Check daily. Or, any sim can learn the Alchemy skill (purchase the alchemy bench in Hobbies & Skills) and create the elixir themselves to drink or consign the elixirs for money. A list of elixirs and ingredients is
here, if you are interested. I usually buy the harvestable ingredients and start growing them right away and work on collecting bugs, fish, metals, and gems as my sims learns the skill. I often have one sim in the household learn the alchemy skill just for the Invigorating and Potent Invigorating elixirs, especially if there are any sims going off to university or tomb exploring in WA worlds.
I've heard there is an opportunity a sim can get to become a fairy, but I've never had it come up for me. To become a werewolf I think a sim can befriend an existing one and eventually be offered to be turned. But for witches (AFAIK) the transformation takes an elixir (or a mod).
Normal sims cannot learn spells or magic outside of using a few items from the Store. Fairies, witches, and werewolves will increase their hidden occult skills by using them, but the sim has to be an occult first. I don't recall if there's a hidden vampire skill.
