In the early days a great deal of nervousness ultimately comes from a doubt that the aircraft or your instructor can cope with the conditions.
After all you believe they should keep you safe - don’t you, but you find yourself wondering if they can cope with that sudden guest. It’s a long time ago, but I remember I felt like that anyway.
Well - you would be amazed at what light aircraft can cope with. You will not even come close to the conditions which are on the edge of the aircraft's envelope. Light aircraft wobble around. They don’t have the inertia and weight of larger aircraft, so that is entirely normal. In really turbulent conditions they will bounce around continuously a bit like a roller coaster ride.
.. .. .. and as far as your instructor is concerned, it is not always apparent how high their skill levels are.
Weather conditions would have to be really severe for either to start to struggle, and you will certainly not be flying in those conditions.
You may also worry about the engine stopping - do you?
Well as you probably know it is very unlikely - and if it does, it is very likely your instructor will do a very good job of landing the aircraft. You may not yet have realised but the average light aircraft can be stopped in a few hundred feet if you really have to, so it is amazing what little space is needed.
They were the worries I had.