How to call an API using Apex?

Could you please explain the process of calling an API using Apex in a step-by-step manner? I'm new to Apex and I'm interested in understanding the basics of making HTTP requests to external APIs. Specifically, I'd like to know how to set up the necessary Apex classes, handle the request and response, and deal with any potential errors that might arise. Additionally, if there are any best practices or common pitfalls to avoid when working with APIs in Apex, I'd appreciate it if you could share those as well. Thank you!