Getting rid of the junk is challenging for a first time liveaboard. I sold alot of stuff and kept what I thought I needed. My 45' boat had loads of storage. Four years later I sold the boat and found that I had completely forgotten about almost all the stuff I had stored aboard. I wound up throwing away most of it. However I did keep a storage unit that housed mostly household items except furniture. That came in handy when I moved back on the hard.
If I had lived aboard a few more years realizing I was going to continue to do so, I would have sold it all. There comes a point of diminishing returns when the rent on a storage unit begins to surpass the value of the stored items. Plus some of the items may be woefully out-of-date when and if you return to the hard. How ever you choose to go about it, it is definately worth the effort to move aboard. It's better than you can imagine!