My suggestion is that you look into getting a NRA Instructor certification. The process of becoming an instructor is relatively straightforward and isn't really that difficult to do. The hardest part is often finding an instructor class near enough to attend.
Go to
www.nra.org and look for the Training Opportunities page. You need to find a NRA Training Counselour. They are the "instructors who teach the instructors".
For what you want to do, even if you aren't actually including any range time, having a NRA instructor cert would help. Besides what you learn in the instructor class, it also speaks to your credability.
I was just approached by the local Republican Party to speak on 2nd Amendment issues at a local party meeting just *because* I'm NRA instructor and my name was mentioned by one of my students.
If you are going to approach civic groups, library groups, etc, and want to speak about firearms issues or gun control, it helps your credability to have some credentials in the subject.
(Granted, the anti-gun speakers might not have any credentials besides not liking guns, but we should be above that and offer more info and less emotion).
My advice: Get an instuctor cert, learn the NRA curriculum, learn more about RKBA issues in general and then decide what parts of the NRA class you'd want to incorporate into your presentations and what other additional info you'd want to include.
Remember, most speaking opportunities are going to have limited time for your presentation. Think 15 to 30 minutes, tops, for most cases, not hour long slide shows.
You'll also need a "slant" or specialized slice on the topic for your presentations and probably more then one. One time you might talk about general firearms laws in your state, another time you might be asked to speak about concealed carry, or another time you might be able to do a longer, more general, presentation on the mechanical history of firearms. Suit your presentation to your audience and their interests.