New Z owner need help with maintenance

[Vvaldez92]

Hello everyone! Like the title says I just purchased a base 2013 370z.

So with that in mind there was 1 previous owner that I got no clue has done.

Seems like my fluids for power steering and brakes is low.
So my question is... And yes I've tried searching this forum for this answer to the best of my knowledge using Google (ex. Power steering fluid? The370z.com)

So I went to my local parts store (pep boys) and bought myself some Prestone power steering fluid and Dot 3 brake fluid. If I just simply add these to what I already have will I have any trouble?

I am not planning on running it like this as I will flush it
Out soon to redline and motul rbf 600. (I have 25k miles)

Another question after some spirited driving on a long lonely street out in my city I notice my steering wheel vibrates a lot when I brake. I'm assuming this has to do with my brakes and why my brake fluid is low. So I searched and decided to get stop tech slotted rotors and project MU spec brake pads.
I have the base model Z so I don't have akebono. Will I notice a difference from stock rotors and brake pads? I plan on changing my Brake fluid at this time with motul rbf 600.

Is there anything you guys recommend? please let me know and thanks in advance!!