How do you use a one time vape pen?

Excuse me, could you please clarify how exactly one would utilize a disposable vape pen? I'm somewhat unfamiliar with the process and would appreciate it if you could walk me through the steps from start to finish. Are there any specific precautions or techniques that one should be aware of when using such a device? Additionally, are there any common issues or difficulties that one might encounter, and how can they be addressed or avoided? Thank you for your time and assistance.