How to buy and sell Ordinals?

Could you please elaborate on the process of buying and selling Ordinals? I'm interested in understanding the steps involved, from creating an account on a supported exchange to executing a trade. Are there any specific requirements or restrictions I should be aware of? Additionally, how do I determine the best time to buy or sell Ordinals, and what factors should I consider when making such decisions? Lastly, are there any risks associated with trading Ordinals that I should be mindful of?