I just found out that if i don't elaborate a perfect strategy, i'm practically f*****d.
Since grass is my type, i chose Bulbasaur as my starter. To have a team, i had to catch a Caterpie and a Weedle (that after i released because i caught a Shiny Kakuna). With no problems i defeated Brock since i was grass, and in Mt. Moon caught a Paras. Reached Cerulian, defeated Misty, and it took all the morning to train my pokémon to a decent level because i recalled that Gary has a Pidgeotto, that luckily i defeated with Ivysaur nearly dying.
So at the moment, i have:
-Ivysaur lvl 24
-Butterfree lvl 20
-Beedrill (Shiny) lvl 19
-Paras lvl 19
I've done a little research and noticed that the only pokémons i can catch are Oddish, Eggxecute, Venonat and Scyther, but the last 3 i can obtain them only after Fuchsia. So yeah, i have to do 3 gyms and travel with 5 pokémon, where only Ivysaur is good and Butterfree is ok with confusion, but the other three at the moment are useless.
I sure had to choose a new generation game, with more possible pokémon to catch and use. And no, i won't accept alliance with other gyms and have a third type, that's my extra challenge. Because yes, i love to kill myself more than i am already. Still, i wanted to congratulate with you, hopelessangelic, for making a nice challenge, even if i'm screwed i'm having quite a lot of fun, feels more like an adventure.