To start: Thank you for this guide.   
Can somebody give me advice please? 
Currently i'm at the 6th gym, The Fortree City Gym. 
All my pokemons get 1 hit KO'd by her. The levels are between 51 and 68, most over 60.  
Even the ellectric type pokemon doesn't stand a chance.   
Is there a good spot to level up those pokemons? I'm getting only 2k exp in the fields, haven't leveled up my pokemons yet.