Wow.....you are way ahead of the curve!
I think I better start with a will....or at least start learning about them
Recommend contacting an estate planner to help walk you through the process. You can always draft up your own and get it notarized. That will be helpful for something immediate, but best have the professionals assist you. Luckily, one of my best friends is an attorney that specializes in estate planning. He pretty much handled everything for me.
I went through two probates in the last 5 years for my grandma and my dad. My grandma had a will, but it was so old that it didn't address "current events" in terms of loans that other family members had on the estate. Then my dad didn't have a will, or at least that we could find. Thankfully, all parties in both probates saw things the same way, which I've heard is usually not the case, particularly when money is involved. In the case of my dad's estate, my sister and her husband didn't want any of the guns. But we still had to go through some hoops to get them released to me. I have a thread on what I went through. It was actually pretty easy, but there are definitely things you can do to make the transition easier. Verifying your registrations are updated (can verify in the "paperwork side") and ownership of the firearms documented.