Where can I buy portal tokens?

Excuse me, I'm quite new to the world of cryptocurrencies and I've heard about these intriguing portal tokens. Could you please elaborate on where I might be able to acquire some? I've tried searching online but the information is quite scattered. I'm interested in both centralized and decentralized exchanges, as well as any other platforms that might offer a secure and reliable way to buy these tokens. Could you provide me with a few suggestions? Additionally, are there any specific requirements or steps I need to follow in order to purchase portal tokens safely? Thank you for your assistance in this matter.