In 1980, 3 friends and I decided to go on a bike tour, went out and bought some panniers, and left the next day for a 6 day 450 mile loop ride. We were backpackers, so we had that basic equipment, but we used highway maps and commando camped every night, never paying for camping. We climbed three big passes, two in one day, and had pouring rain, hail, and very hot weather. We had no how-to books and regular 10 speed bikes--Nishike, Motobecane, Pugeot--bikes that cost about $100 at the time and lasted us for about 20 years! We had a great time and loved every moment of it, except for the moments we hated. I'm the only one still at it. One died about 10 years ago and the other two got out of shape and haven't toured on years.
In 1973, I took my first "tour", though. It was a "kinda" tour; a friend and I rode 50 miles to another friend's house, spent the night, and rode home the next day. I'm not sure that really counts.
In the early 1940s, my mom and some college girlfriends toured for several days through parts of Western Washington. They had some adventures, including a broken frame they got some guy in a shop to weld back together.
So, I'd gather my stuff and take off. That's the best way to learn.