Great topic! I know that @HankG is planning his first bikepacking trip, I'm sure he'll appreciate this thread!
My first bikepacking trip was over Resurrection Pass on the Kenai Pennisula in Alaska om 2017. A friend of mine and I drove 8 hours from Fairbanks, loaded up our bikes and headed out. The trail is basically 20 miles up and 20 miles down of incredible backcountry singletrack. We, foolishly, thought we could ride 20 miles up, make camp, and then finish with a nice day of downhill. I made it maybe 8 miles before my quads cramped so bad I was reduced to a pile of tears and shame on the side of the trail, cursing my poor hydration and the mosquitos. We ran into two mountain bikers on their way down, who graciously offered the use of their cabin reservation that they no longer needed. We slept peacefully on bunks with a fire in the woodstove keeping us warm and dry. The next day was a long but amazing ride and made me forget the suffering of the day before (so much so I came back the next year and did it again!). After that I was totally hooked and have done several other trips around Alaska. Now that I've moved to Washington I'm looking forward to discovering all the bikepacking routes it has to offer as well!