to the forum. After sitting idle for 3 years, I'm sure you'll find a number of things that aren't "quite right" with your RV. Hopefully, nothing serious will be found and you can get back to camping with little "discomfort"
As you find problems, check the search feature and review what other members did to help resolve their problems. There's a wealth of information available here, free for you to use, so enjoy your time with the forum.
If you can't find what you're looking for, ask a question, give as much information as you can and you'll most likely find answers forthcoming from members who have experienced much the same issue.
Good luck getting that "idle trailer" back on the road and working perfectly.