How to buy on 1 inch?

Could you elaborate on the process of purchasing cryptocurrencies on the 1 inch platform? As a newcomer to the world of decentralized finance, I'm curious about the steps involved in making a purchase. Do I need to create a wallet first? How do I ensure the transaction is secure? Additionally, how do I know which cryptocurrencies are available for purchase on 1 inch? And finally, what are some of the key considerations I should take into account before making a purchase on this platform? Your guidance would be greatly appreciated.