Mastering a track

When I’m done with a track and i want to use mastering software like iZotope, do i master it first and then apply effects/automation later or what =/

Not sure exactly what you mean.

But it’s common practice to have automation and the likes first on each of the tracks. When it’s done you have the final mastering of the entire song.

You might wanna watch some vids from the training videos or on youtube.