Just inspect and replace as needed. All the usual suspects. When I got my truck I did a full tune up, oil change, new belts, new trans/diff/radiator fluid, inspect the alternator and battery visually and with a meter and under load, check pulleys and tensioners, check driveline in case it has grease fittings. Check wheels and tires to make sure they are road worthy (rotate if needed), check brakes and pads/shoes, inspect brake fluid and change if dirty/old, new air filter, clean maf, inspect vacuum hoses, clean IAC valve, clean throttle body, run fuel system cleaner through it, check to make sure AC works properly, same for heater, aaaaand theres plenty more i'm sure but most of these are essential and most are very cheap or free to do. I didn't knock all this out on day one but I did most if not all of it within the first month of ownership.
No sense in throwing parts at it when they aren't broken where theres plenty to repair/replace/refresh already.