Congrats on the new car and welcome to the community!
I'd say keep it 100% stock for the time being, especially if you are afraid of voiding your warranty. Eh, life's too short, mod it how you like
By keeping it stock, it'll make you appreciate the car as is. Through experience with the car, you'll know what mods would work for you. It would depend on your vision of your car as well(i.e. Track, Stance, DD, etc.)
I didn't mod my car until around 6 months or so. Even then, it was just minor mods.
My recommendation for a first mod would be a Catback/Axleback Exhaust. Having an exhaust wouldn't give much power gains but it’ll definitely make it sound better.
My recommendations for future mods:
- Header and tune
- Wheels
- Tires
- Suspension
- Brakes