How to buy and sell on OKX?

I'm curious to know, could you please provide a step-by-step guide on how to buy and sell cryptocurrencies on OKX? As a novice in the field, I'm interested in understanding the registration process, verifying my account, depositing funds, placing trades, and ultimately withdrawing my assets. Additionally, I'd appreciate any insights into the platform's fees, security measures, and any special features that may be beneficial for traders like myself.