What is a typical first lesson for glider flying like? Does it usually include a pre-flight mini lecture on basic theories at all, or if not pre-flight, do instructors usually spend some time on the ground teaching related theories at some point of the lessons?
I understand it may appear as primarily opinion-based to some, but input from instructors or past-students with a similar experience would fall under 'specific expertise' and thus I think insightful answers are possible.
I'm a glider instructor. The first lesson would have been introductory and if there weren't any soaring conditions, I'm guessing the flight was pretty short, less than 15 minutes, so you probably did/saw a lot less than expected. It's a challenging instructing environment because of the time limitations on no-lift days.
If you were disappointed with the instructor, note that in glider club operations you will generally fly with all of the club's instructors at different times and you will end up with a couple of favorites.
At least give it enough time to experience a good soaring flight with an instructor to find out what the potential is, and whether you think you can get hooked on the "game" you play with the atmosphere to stay aloft. Some pilots get into it, some don't and would rather go with power. Not much different from sail boats vs power boats. Me, I like both but if forced to choose, I'd go with soaring as a fun activity.
Assuming you are into it because you are interested in the sport of soaring, you should hang in until you are solo and get a good soaring flight by yourself. The first thermaling flight on your own, climbing in many tons of rising air, is an incredible rush, more than first solo in my opinion. Of course it all hinges on whether you get hooked on the game itself, of working the air to climb.
No two flights are ever the same. Watch the private owners go out in their high performance machines and disappear for an entire afternoon. 4 hours in a glider is not like 4 hours in a power plane that beats your brains in with noise and vibration; it's like 4 hours of meditation - you return very relaxed and mellow.
Even if you don't think you'll take to the sport, and you plan to learn in power planes at some point, learning to fly gliders first will make you a far better pilot with respect to basic stick and rudder skills, speed control and energy management, so it's worth sticking it out just for that.
It would help to compartmentalize your approach here. When around the plane and especially when flying, do what your instructor says! It is extremely important to build that trust. Put yourself in the instructors shoes. They have no idea what a new student will do and are literally risking their lives taking you flying. Don't forget crashes and fatalities are a very real part of aviation. Don't expect extensive explanations while flying.
Do save your questions for post flight discussion and make this part of each lesson. It would also help to commit to a program (flying school) towards a goal (pilots license) and spend time in class learning theory.
But for an intro, they are most likely just taking you up for a ride and seeing if they can work with you. Yes, some will see you as a one timer and not treat you the way you like, but it's a two way street and it certainly will take more than one lesson to learn everything.
Once you find an instructor you are comfortable with and commit to a goal, you are on your way. By all means, don't expect it to be completely your way.
