Numbers after the name of a course, class, seminar, etc. usually indicates the course number in a series with the same name. Numbers less than 2000 indicate community college while 2000 and above are university/college level.
101 is the lowest possible number and is used to indicate something is the most basic of beginning tutorials, classes, or seminars.
Classes at an American Universities have numbers that are part of their titles in the course catalogues. Those numbers tend to run from 100-900. Courses that have the 100-199 numbers are beginner classes. If I am a first year student at an American University, I would have to sign up for Korean 101, because my Korean is terrible and I need to start at the basic level. However, I might need to take Chemistry 202, because I am an advanced chemistry student. Survival 101 means that something is a basic survival skill.