Oh god… the Rock Tunnel. Zubats, Zubats everywhere.
As a funny anecdote, the first time I played Pokemon Red, I didn’t got Flash until later. I crossed all the goddamn tunnel in darkness. I was following the walls until I managed to find the exit. Dear god, the patience I had was simply baffling.
Got my pokemon healed, explored the tower a little and fought my rival. Nothing great. Headed to Celadon to get my first badge but first I cleared the Team Rocket Hideout. Before that, I made sure to get Eve and evolved it to Jolteon, same with Tesla to Raichu; checked their stats and decided to keep Jolteon. I have always liked this stage.
This is the team I used to face Erica.
Terra ♀ lvl 30
Thundering ♂ lvl 27
Zatana ♀ lvl 34
Soulblaze ♂lvl 36
Queen ♀ lvl 28
Skydancer ♀ lvl 25
Things went smooth with Soulblaze and Skydancer.