I have medium brown hair, will a semipermanent pink dye have any effect?

If it does, how do i do it right? If not, what should I try (i dont want to bleach it)

I have medium brown hair, will a semipermanent pink dye have any effect?

There will be no one-step process to get your hair pink. Gotta bleach it to make it show.

I have medium brown hair, will a semipermanent pink dye have any effect?

It will only have a light pink haze to it, that you would see in the sun, but very little. You would have to actually lighten your hair either by hair color or bleach, then applying the semi permanent after that, the higher the level the lighter you hair will turn out to be.