Start by going thru everything including clothing and have one or two huge garage or yard sales. Then what's left: 1. give to charity or someone in the family. 2. throw away 3. keep. The "keep" pile should be very small. Small enought to fit in an RV. I would NOT put anything in storage. Waste of money. Scan important papers and photos. Some things you will need on the road: Good internet provider for online banking, etc. and satellite TV if you care about watching TV. We use a Verizon Mi-Fi and DirecTV. Start getting rid of junk mail. Send notices to catalogs and magazines to take you off their mailing list.
Decide how you will get your mail. If you don't have a family member, you can use UPS or check with www.myrvmail.com for more info so you will at least know what to ask and what forms need to be completed. Insurance for full timers is different. Some insurers don't cover full timers. We use National Interstate Insurance Company. They insure the RV and the toad and include Coach Net roadside assistance in their premiums. You can purchase their insurance through an agent. Decide if you want your residency to remain in WI or move to another state. Make lots of lists and cross off things as you do them.