Ryanair has a good safety record, so you will be alright. If you are scared of flying and of heights I would recommend that you do not sit near a window; but I always love viewing the scenery, its beautiful. I also recommend that you bring some snacks to munch on during the flight, if possible. The interior of Ryanair is very nice, their fleet consists of many new Boeing 737s, you should be set out to be on a clean comfy ride. Try not to think of the 'what ifs' during the flight, just take out the emergency card in the seat in front of you so that you are aware of the safety procedures, and afterwards maybe you can read the inflight magazine and munch on something like I said. If you are traveling with family or friends, or even if not, start a conversation with your neighbor. It will kill some time. Another great idea, one of my personal favorites, is to sleep! I have been flying on planes since the day I was born, so I never had the fear, but the best advice I can give you is to fly more regularly. The more you fly, the less the fear; its almost like when people say "practice makes best!". Well, I hope you have a wonderful experience, flying is great!