I agree the amount of driving depends on your tire wear at most also if you're looking for race, speed, show.
It's different with different tires and wheels.
Do the normal checks and have proper tire specs on the wheel. What are the speed ratings, size, width, pressure, diameter, capacity load.
Maintain them normally
1. Rotate, Balance, Torque wheels all appropriately
2. Air Pressure
4. Valve stems, Race stems, Etc...
5. Visual, Touch, Hearing
Just watch them normally if the tread on the inner wall is torn or looks shredded then it's no good. You can do the "nickel or penny check" and to meausre the thread loss to see how much you loose in a certain amount of time. Once you have them on the car you'll tend to know when you need to change tires if you do the normal maintenance and checks. It all depends on your driving and how often you do some of these things.
Here are some sizes i'd prefer remember depends on the rim as well 1,2,3 piece rims, weight, etc.
18x8.0 These sizes should be fine that would be the largest & widest i'd go on a stock Celica. Suspension mods will help a whole lot and tires will be based on your preference since they're are to many to choose from with so many different specs. Every maker promises different things do some looking around match a couple to see what fits your preference.