A Lead Generation or "Lead Gen" Funnel is used to build a connection with your potential customer. People often refer to this method as offering an "ethical bribe" such as the familiar "free sample" in an ice cream store.
The idea is that you give away something valuable in exchange for an email address. (Then you use that email address in ethical ways, to build a relationship with your customer. Do NOT spam or sell the email address.)
Use this type of funnel to give away a downloadable item, such as a PDF booklet, a training video, or spreadsheet on a sharable Google drive link, etc. The possibilities are endless. Use your imagination.