Could you elaborate on the steps involved in purchasing tokens on the Radium platform? I'm new to the cryptocurrency scene and would appreciate a concise yet comprehensive guide. Specifically, I'm wondering about the initial setup required, such as creating an account and connecting a wallet. Additionally, I'd like to understand the token listing process and how to identify which tokens are available for purchase. Furthermore, could you provide any tips on ensuring the transaction's security and minimizing any potential risks? Lastly, I'm curious about the transaction fees involved and whether there are any promotional offers or discounts for new users. Thank you for your assistance.