I just bought an 06 coupe with 66k miles. Pristine condition

It purrs like a kitten but I am super paranoid about it blowing up for (admittedly) no reason at all. What things can I replace / check to ensure that I have taken every possible precaution?

I "think" I hear a ticking but its so faint that I may be just a crazy hypocondriac... it seem to be coming from the passenger side of the engine if that makes any sense. Not grinding or anything, just a tick tick tick (very faint). Could it just be the engine doing it's thing?

Transmission fluid has been done.
Throttle body scheduled maintenance done.
Oil clean and full. 5W-30 synthetic.
Needs power steering and brake fluids changed, possible coolant.
belts are tight and in good condition.

NO engine mods done as of now.

Apologies for the newbstorm but I want to do it right from the start

Cheers!