First and foremost congratulations on the new rig exciting times ahead
You didn't mention whether you are currently renting? In the process of selling your house? Keeping your house and renting it out? In other words what your status is as your starting point before going FT.
With regards to domicile there are various options, we are Canadian but many of our US friends have told us that how their health insurance works dictated somewhat on whether they Domiciled in Florida, South Dakota or other states = in other words not just the kindest taxation state for their needs.
As for address depending on where you decide to domicile, there are escapee mailboxes and other mail box providers that others doing what you are about to embark on will be along shortly to share with you. Most of us use a relatives address (children, siblings, etc) as if we rent a room in their homes to meet the need. Again it will all depend on what's most beneficial for you overall on where you decide to domicile, taxes, health care, vehicle registration, convenience etc etc.
As for insurance do make sure there is no doubt that the insurance company you go with (not always the cheapest!!!) is good and in writing for Full Time usage of your rig! If you need to claim in the future you don't want any issues at that time! Again many others will respond soon with who they use and why or if they've recently changed why the need to have done so. Insurance is a moving target on coverage so check it every year upon renewal to make sure you are adequately covered for your needs.
Storage = this is something you might want to seriously spend time deciding on what is the best thing to do. So many folks over the years have said to us if they had to do it over again (those that stayed on the road several years) they wouldn't have kept anything in storage except maybe a small tote box or two at a relatives house of tiny treasured momentos or must keep hard copies of documents. Most folks scan everything they need to and have several copies located in various places (thumb drives, cloud etc). Their reasonings after the fact are: a) What it cost in storage fees wasn't worth it. b) Having to go back to the storage every so often to try and downsize to save $'s. c) The items they kept got damaged during storage time d) The furniture and items kept and paid for didn't fit in their later home or were too dated a decade plus later.
Emotionally it was a huge rollercoaster for us having to dispose of our treasurers and inherited/sentimental items that our kids just have no connection or interest in keeping in the future. Watching folks rake over our prized belongings in garage sales we had and what was left dropping off at Charity places etc. Heart breaking but with time soon got forgotten as once it's gone it's gone, and time to create new memories down the road.
We had boxes/drawers for several months, that we put things in as "need on the road", "might need on the road" "haven't used for a looooong time". Over time things got moved from one box or drawer into another until the eye opener was truly how little we use on a regular basis and how some items can be used for multi tasks. Trying to keep the amount moving into the RV weight wise as low as possible.
Lots of folks take waaaay too much clothing, bedding, towels etc. With your clothes divide your wardrobe into sections, and you'll find there's probably less than 10% you have as your favourites and the rest don't get used more than once every few months or often not for many years. Be ruthless in getting rid of that you really hardly ever touch/use.
Don't become overwhelmed. Make your list of things to do and subset points for each category and notes, and just work on one item at a time = adding and crossing off as you go. Best way to eat an elephant is one bite at a time. You'll get there and anything you don't have onboard when you finally depart and need, there's always Walmart as they say.
Congratulations on the Highlight of your Twilight