If you are a new fan looking to see where the madness began, you should know that episode 1 ("Cartman Gets an Anal Probe") is often listed differently on streaming services due to the original pilot rights. Look for the "uncensored" versions.
The series grew from two low-budget animated shorts titled The Spirit of Christmas (1992 and 1995), which became some of the first "viral" videos on the early internet. South Park - Season 1