Can I convert my BTC to USD?

I'm a bit new to the cryptocurrency world and I'm curious about something. Could you please tell me if it's possible to convert my Bitcoins (BTC) into US dollars (USD)? I've heard about exchanges but I'm not quite sure how they work or if they're reliable. Could you explain the process to me? Also, are there any fees involved in this conversion? And how long does it usually take to receive the funds in USD? I'd appreciate it if you could provide me with some clarity on this matter. Thank you!