Do you have a general area of interest?
If so, then a great way to begin to define your topic or find topic ideas is by conducting exploratory research.
Thoreau is best used for exploratory research or undergraduate research.
Type keywords relating to your general area of interest to begin exploring the literature.
Are you interested in a topic relating to the subject of education? Try the Research Starters database. Search with broad keywords like assessment, retention, literacy, etc.