How to buy altcoins safely?

Could you please explain to me the steps I need to take to safely buy altcoins? I'm new to this and want to make sure I'm doing it right. Should I be using a specific cryptocurrency exchange? Are there any red flags I should look out for when choosing an exchange? Additionally, what are some best practices for storing my altcoins securely once I've made a purchase? And finally, how can I protect myself from scams and fraud in the altcoin market? Thank you for your help.