In order to get a successful search going, you are going to want to make a list of related words after you narrow down your topic. Ms. LaToya has suggested that you write your paper first and then insert the evidence to support it So, for example, if you choose the first prompt about the power of love in mythology and in Romeo and Juliet, you might want to narrow down "mythology" to a specific myth, maybe a story with Venus or Cupid or use keywords words for your supporting evidence. The more keywords you can gather, generally, the better your results will be.
Wikipedia isn't a reliable source, but it can be a good place to get hints on keywords to use. If your initial search isn't turning up, make sure to try synonyms before giving up.
Remember to use the tools that these sites both give you- save the sources so that the programs can format and alphabetize it for you. Make sure that you look over any autofilled-in information.