Also the largest arc is six episodes long. Largest in the whole series. So short and amazingly paced arcs are aplenty.
Ooohh ooh once you have been introduced to a character named Okita Sougo (vice chief of shinsengumi ie the police) and majority of other shinsengumi guys like Toshiro Hijikata and Isao kondo, watch episodes 86 and 87. :D
HEY YOURE WATCHING GINTAMA. IM SO HAPPY RN. ;; the episodes will range from okay to slightly good for a while till all characters get introduced. Actually once all main ones are introduced, i recommend arc jumping. It isn't a huge interconnected storyline so arcs are standalone. As long as you know the characters, you should be able to pick up any arc and enjoy to the fullest! I started arc jumping around ep 30ish. You can start at 20 something maybe :p