ALSA here are some things you can think about.
It's very probable that during the flight the aircraft will encounter turbulence and which feel like a VERY bumpy ride. The human instinct feels that it is unsafe,but it is not. An aircraft flies just as good in calm air as it would in turbulent air. It wont tear the wings off

Flying in turbulence can be looked upon as riding on a strong motorboat in a storm. The waves will throw the boat around quite a bit, but it sure still floats :)
When you have boarded the aircraft the most 'dramatic' thing event before actual take off is when the engines starts. Air condition will stop working and the lights in the cabin may go out for a few seconds. This is completely normal, engines need the air pressure to start up (pneumatics) and the lights goes out becuase the pilots switch power sources.
It's not un-common to sense the smell of smoke in the cabin during the taxiing, however it's not your aircraft that's on fire, you're just smelling the exhausts from an aircraft infront of you :)
You may hear some sounds coming from the wings, it's just the sound of the flaps getting extended.
Time for takeoff, the aircraft taxi to the runway...it may stop for awhile. Engines are revving up, and the jet starts moving. The sound is unique it will be a total new experience for you, bumps from the runway will make the aircraft shake quite a bit and it feel like the pilot is pushing it to the limit...but alas that's not true aswell.
As the pilot rotates the aircraft upwards it may feel like you're flying with a 45 degree angle, but it's just around 15 degrees infact, the landing gear will make some thumps when they retract. Suddenly without explanation the noise from the engines will decrease and the plane appears to slow down and fall from the sky. It may not happen on your flight but it may very well do. But this is a normal operation.
See, the pilots reduce the engine effect and level off abit to comply with noise abatement restrictions. The aircraft is not slowing down it's going faster and it's still going upwards but not as much. The aircraft don't need all the engine power anymore, but it needs to gain some speed before it can continue the climb without the addition lift generated by the flaps
The aircraft now has enough speed and lift so the flaps aren't needed, so you'll hear the same flap sound again :)
As the aircraft approaches the Canaries the flaps are again extended (in increments), if you sit at the wings you can see the large metal high lift devices, aswell as the spoilers. Gear is extended so that will again generate some noise. This is where the trip is likely going to be as most shaky, but no needs to worry mate.
Even the most experienced passenger can get a scare when the aircraft lands and suddenly take offs again. These manouvers are called Go-arounds are are more common than you think. The pilot may have elected to do that because of sudden wind change etc.
But I can guarantee you that your trip will be trouble free, there's no safer travel than flying, and I really hope you enjoy your trip!
Take care :)