You have to beat the 2nd gym.
26
head west of cerulean city to the Rock Tunnel
The third gym is in vermillion city. The Gym Leader is Sarge, and he uses electric-type Pokemon.
No you sholudnt have to because you just have to have more than 1 Pokemon in your party, trade with a friend!!
no
they should be at their highest stage and at least lv.40 to win easily
it is in saffron
In his Gym in Cinnabar.
the thunder gym in in vermillion city
In the cinnibar island gym.
beat the gym leader