How do I transfer my Crypto to metamask?

Could you please elaborate on the process of transferring cryptocurrency to a MetaMask wallet? I'm interested in understanding the step-by-step guide, starting from the initial setup to the actual transfer. What kind of preparations do I need to make? Do I need to have a specific cryptocurrency in mind or can I transfer multiple currencies? Are there any fees involved, and if so, how are they calculated? Finally, how can I ensure the safety and security of my funds during the transfer process? I'd appreciate a detailed answer that covers all these aspects.