You don't really NEED to know it, but if you are curious you should watch the episode The Cage and the two part episode "The Menagerie" (in that order) . But besides the Pike story there are only few references towards other Star Trek Media. Season 3 Episode 3 for example is highly connected to Star Trek DS9 (but sadly filled with major continuity errors), but you would get the plot without seeing those older episodes.
SPOILER:
the Cage gives back ground information bout the inhabitants of the planet, and The Menagerie is about a crippled near Death captain Pike who returns the planet where he could survive and lead a normal life with a woman he has feelings for.
The Cage gives back ground information about the inhabitants of the planet, and The Menagerie is about a crippled near-death captain Pike who returns the planet where he could survive and lead a normal life with a woman he has feelings for.
