Besides buying a coin on a creator's coin page, you can also buy a new coin from the Trade menu, which is located at the top right of the website (when logged in). You can even buy a new coin from the Trade menu before the creator’s coin page has been published.
Note: For further context, see Overview of How New Coins Launch.
To do so:
Log in and click the Trade button at the top right of the page.
Under Creator Coin, click Buy or Convert. (Buy allows you to buy with a credit/debit card or cryptocurrency, while Convert allows you to buy with $RLY from your Portfolio. For the latter, you must already have $RLY in your Portfolio.)
In the list of coins, scroll or use the search function to find the 3-5 alphanumeric characters that make up the “symbol” for the new coin. (New coins have no designation that they are a new coin.)
Complete the transaction.