How do I get on Dex?

Excuse me, could you kindly elaborate on the process of accessing a decentralized exchange, or Dex for short? I'm a bit new to this and I'm not sure where to start. Could you guide me through the steps, perhaps highlighting any prerequisites or security measures I should be aware of before embarking on this journey? I'm particularly interested in understanding the process in a comprehensive yet concise manner. Thank you in advance for your assistance.