Keep a list of possible search terms and add to the list as you read new information. Keep track of what you search and where so you can circle back and do new searches with an updated list of search terms.
Keep track of all your sources using Zotero or End Note, or at least keep them together in a folder on your computer/in a list with citations.
Have you already spent 20 minutes searching and you feel like you're hitting a wall? Stop & contact your librarian!
Research takes time, and when you're working on research for a paper you might spend hours researching and try many, many searches before you're done. But you shouldn't spend hours searching and finding nothing. If you spend 20-30 minutes on your research and you're not finding anything remotely relevant/close to what you're looking for, please stop & contact your librarian! I can help you develop search search strategies, and maybe choose another database more suited for your topic.
Before you dive into the databases looking for scholarly, peer reviewed articles, do some background research! Knowing how an issue is being discussed in the field and what interventions or policies are already being recommended will help you when you search the databases. The Encyclopedia of Social Work is a great place to start, you also might try an open web search on [your issue] intervention policies or something similar. This is likely to bring back reports from think tanks, non-profits, and government agencies interested in the issue. When you find a report from a think tank, research institute, or similar source, consider looking them up on Media Bias/Fact Check. This site will tell you whether the organization is known to use mostly factual information (or not!)
Once you have some background information, and maybe information from government and other policy sources use the key terms (and maybe even interventions!) you've identified to find research and information from scholars and practitioners working in the field.
Some databases will include the full-text of articles, but others will include the 
button which links to full-text when available and if not available, gives you the option to request articles for free through Interlibrary Loan's Illiad service.
Keep track: Keep a list of the databases and search terms you used, that way you'll know what you already tried and where you had success!
Quotation marks: “affordable housing” searches for the phrase affordable housing. Searching without quotation marks will search for affordable and housing anywhere in the record.
Asterisk: homeless* searches for homeless, homelessness, etc.
Question mark: wom?n searches for women and woman
Save what you find: Use a citation management software (like EndNote or Zotero) or other method that works for you to keep track of articles and books you find.
Trace the Literature: Use an article’s reference list to find additional articles & use a citation database/index (like Web of Science or Google Scholar) to find a list of more recent articles that have cited a given article.
Local news articles may give you more information about previous programs in your neighborhood, local organizations working on your issue, and more context about the area.