seeing bitcoin prices go down and up, I'm a bit frightened to buy bitcoin at the moment, I judge I could lose, do you think, whether bitcoin prices can continue to go down, or even rise high?
As many people have said, BTC and crypto in general, is pretty volitile so there's no way to predict what will happen. However, with that said, I personally believe it will go up over a longer period of time, and so if you buy now, I would expect your investment to increase in value over the next few years.
Alternatively, you could watch the exchanges for a while and attempt day trading with small amounts and see how you get on.