In general, a search engine, like Google, is a good place to start. You will likely be looking for specific information, or you will be looking for guidance on how to find specific information. Library guides are fantastic sources for the latter. To find a guide on a topic, run a keyword search for the topic along with some search limitations. The search limitations should indicate where from where you'd like to receive guidance on how to find information about a topic. For example, a search that includes inurl:libguides will return guides created by libraries; a search that includes site:edu will return results from academic institutions.
Together, if you wanted to find guidance on how to conduct informal fact research, a search might look like:
fact research inurl:libguides site:edu
This example search query will return guides from academic libraries on how to conduct factual research.
Students in the Mortgage Foreclosure Clinic can find more research resources here: Mortgage and Foreclosure Resources: Research Sources
Guidance from experts is one place to begin when you don't know how to find specific information for the topic you are researching. These articles provide insight and resources from experts. The links below provide you with further resources, tips, and training for conducting factual research.
Gizmodo article: How To Find Anyone Online by David Neild offers some good tips and resources for finding people online.
Sometimes Google is not the be-all and end-all of search engines. Read about 13 alternative search engines that might find for you what Google cannot.
The Most Complete Guide to Finding Anyone's Email Address offers many suggestions worth reading.
Practice makes perfect: Run a Comprehensive Background Check on Yourself
"Although many [Facebook] groups are private and you might need an invitation or a source inside them to gain access, the world’s largest social network is a trove of publicly accessible information..." Learn more here: https://thegroundtruthproject.org/tools-tips-digging-facebook-two-investigative-journalists/
In the real world, if you cannot make it to an academic campus whose databases would be available for use at a public computer terminal, you might want to consider visiting a branch of the local library system. Often, they have subscriptions to databases that you may access from their own public computer terminals. You might also wish to consider speaking with a Librarian, as they are in the profession of thinking about information and where to find it.
These guides are jurisdiction-specific, but may be helpful for clues on how to try to find specific information on a topic in your jurisdiction.