If you are "nervous of stocks" you should educate yourself and become not-nervous.  If you do that successfully, then you are ready to invest in the stock market.   

You don't "lose money" in the stock market when markets fall.  You lose money when you fail to have an investment policy you understand and agree to align with, an asset allocation that reflects your risk tolerance/age/stage, and enough knowledge and control to not be influenced by short-term thinking or random editorial advice.  

You "lose money" when you make bad decisions without those basic pillars in place not when "markets fall" and you get "nervous".