I think you want to say
I want someone who can speak in Japanese together.
私は(I) 日本語で(in Japanese) 一緒に(together) 話せる人が(someone who can speak) 欲しいです(want)。
I'm Japanese native speaker.So I can teach and talk with you.And I want some one who can speak in English with me.
I want to be your friend!!
You wanted to write ほしい but this is combined with nouns not verbs. See here the difference between ほしい and -たい: https://www.learn-japanese-adventure.com/japanese-expression-desire.html