Chapter 4 of Morris Cohen and Kent Olson's Legal Research in Nutshell provides an excellent overview of the publication process of statutes,  conducting statutory research online and sources for federal and state statutes.  Legal Research in Nutshell is available digitally through Westlaw Study Aids Subscription. The library has a physical version in the study aids section behind the circulation desk.

Federal statutes are organized, by topic, into Titles.  There are currently 54 Titles in the U.S. Code.  Within the statutory citation, the title number precedes the U.S.C. abbreviation.  The next number in the citation is the statutory section as illustrated here.

Citations to state statutes varies from state to state. See Table 1 of the Bluebook for the title and organization of state statutes.

Keep records of your work throughout the process. Make notes of the source you searched, the search terms you used, and your results from each step. 

This will keep you from having to repeat steps and will help you recall what search terms you used. If you cannot find a definitive answer, you will be also able to report on what you did find and where you looked.