You can buy cryptos at any exchange. The easiest way and safest (in a legal sense) is Coinbase. Just go to https://www.coinbase.com/ and create an account. Link your account with your credit/card or bank account and you’re good to go! (See more: Crypto Guide 101: Choosing The Best Cryptocurrency Exchange)
We’re also in the midst of releasing a comprehensive guide on how to get started investing/trading in cryptocurrencies, since we understand that the crypto world is very intimidating, especially for starters. We’ll keep you updated!