How do I transfer Crypto to Gemini?

Could you please explain the process of transferring cryptocurrency to the Gemini platform? I'm interested in learning the steps involved and any precautions I should take to ensure a smooth and secure transaction. Is there a specific wallet or account required? Also, are there any fees associated with the transfer, and how long does it typically take for the funds to be available on Gemini? I appreciate your guidance in navigating this process.