How to buy sei on astroport?

Can you guide me through the process of purchasing SEI tokens on Astroport? I'm interested in getting started but not sure where to begin. Are there any prerequisites or requirements I need to fulfill before I can make a purchase? What are the steps I should follow to buy Sei on this platform? And what kind of fees or charges should I expect to encounter during the transaction? It would be great if you could provide a comprehensive explanation that's easy to understand for someone who's new to this.