Hi everyone,
I am finally a proud new owner of a 2007 350z, which is my dream car since i was in high school.
Anyways, I need some suggestions on what i should do first to this beautiful car cause to tell guys the truth, I have no idea on what i should start first??????????...... Decisions decisions.

Really depends on your budget....

On a small budget:
DE lower plenum
Blox plenum spacer
Cxracing hks knockoff
Pop charger
AEM o2
Apexi SAFC
Test pipes
EBay n1 lip

On a larger budget:
UTEC
MD mrev2
MD plenum spacer
Stock CAI with one of those dry nanofibre filter things
Cams
MD res.Test pipe/HFC y or yz pipe setup OR longtube headers
AAM 3" single
BC racing coilovers
forged aluminium with lightweight tires
25mm F, 30mm R spacers
Lightweight clutch and flywheel combo
Lightweight rotors
...list keeps on going

Build sheet, build sheet, build sheet.

Have a overall direction you want to take the car and plan accordingly or you'll wind up with a haphazardly constructed pile of randomness. Seen it happen too often not to mention it.

Welcome to the Z family and NICO!