Where can I buy XLM and XRP?

Excuse me, I'm a bit new to the cryptocurrency world and I'm looking to purchase XLM and XRP. Could you possibly enlighten me as to where I can acquire these two cryptocurrencies? I've heard they have some promising potential, but I'm not sure where to start. Are there any specific exchanges or platforms that you would recommend for purchasing XLM and XRP? Additionally, are there any safety measures or considerations I should be aware of when making these purchases? I appreciate your assistance in guiding me through this process.