Congratulations. You made a good choice. We retired early and never regretted it. We volunteered for national and state parks off and on for our 16 years of full-timing. It's an awesome experience. There are many wonderful opportunities out there and you get to choose what you want to do. We've given lighthouse tours, lived on an island, played with the fish at a Fish & Wildlife gig, toured Lake Powell on a houseboat, pulling a speedboat for siteseeing those fascinating coves (yes, while volunteering), walked trails and just chatting with other hikers, and many more wonderful 'jobs'. It gives you a worthwhile feeling to help others to enjoy the parks. You'll love volunteering. It sure beats sitting and watching t.v. all day.
I can't believe the two comments made about how awful hosting 'must be'. They didn't even do it. How do they know? It is nothing like they 'imagined'. Volunteers have choices as to the jobs they perform. If they don't like a particular one then don't apply for those kinds of job. There will be others who don't mind doing them. The purpose of volunteering isn't a free campsite. It's helping.
Best of luck and have fun in your new lifestyle!