If you are scared of losing any money. Then do not put any money on an investment that you are not comfortable with.
Agree. If we are afraid, don't force ourselves to invest. For example investing in new altcoins, it has a big risk to lose money. So, it is better to avoid investing in new altcoins, simply choose top altcoins or Bitcoin for investment. These types of coins are safe enough for a long-term investment, so we don't need to feel doubtful.Do not base your decision with other people's opinion and research. If you do that, you'll most likely end up being broke and in vain 
Yes, it is a must. Always decides to buy any coins based on our own research/analysis. It is a fundamental principle in investment.