How do I buy a small amount of ETH?

Could you please explain to me, in simple terms, the steps I should take if I want to purchase a small quantity of ETH? I'm not very familiar with cryptocurrencies and finance, so I'd appreciate it if you could keep it as straightforward as possible. Could you outline the process from setting up an account to actually making the purchase? Also, are there any specific platforms or exchanges you would recommend for someone like me who's just starting out? And, just to be safe, what security measures should I be aware of while making this purchase? Thank you in advance for your help!