I usually always plan on replacing the “soft” parts; tires and tubes and grips/tape. Fresh brake pads are cheap and easy to install and make a huge difference.
Definitely pack some fresh grease into the hubs and crank bearings, headset, too.
I wouldn’t plan on a full drivetrain replacement unless things are really worn / rusty. Stiff chains can be loosened up with a soak in ATF.
New cables are always a good idea on a bike that old; Ten-speed era bikes are pretty simple, and even an inexpensive cable kit will make it happy.
A lot of of what I do depends on what the bike is going to be used for. If it’s going to be a campus cruiser that spends its life on a bike rack, it will certainly get a different state of tune (and fewer replacement parts) than a bike if, say my kid wants to ride Cap2Cap or an MS150 with me.