On NonFiction Authors Association site:
Whether you want to speak for free to sell books at the back of the room or you want to get paid to speak, there are many ways you can locate speaking opportunities.
When you do locate opportunities, don’t be afraid to pitch yourself via phone or email. Just make sure you’re prepared with an excellent speaker page on your website, a list of your speaking topics, professional photos, and video clips of you in action.
If you don’t yet have video clips, focus on booking some free local gigs in order to gain experience and get some video you can use later.