How do I buy a legit domain?

I'm interested in purchasing a legitimate domain for my online business, but I'm not sure where to start. Can you walk me through the process of buying a domain that's both reliable and trustworthy? What factors should I consider when choosing a domain registrar? Are there any specific steps I should follow to ensure that I'm getting a legitimate domain and not falling victim to scams? Additionally, how can I protect my domain from being stolen or hijacked in the future?