Toyota Repair: 93 Toyota Corolla, spark plug wire set, spark plug wire

Question
I just bought a pre-owned Corolla, mileage is 112k miles. I don't know anything about cars. How many miles should I change my spark plug wire set, and how to observe whether it should be changed?  And I don't know if I need to change the distributor cap and rotor too, but I don't know what they are. The mechanics told me to change all those things. But I don't wanna repair the unnecessary things. Thanks.

Answer
There is no set mileage recommendation to replace those items and are not normally replaced unless there is a driveability problem, the mechanics are telling you to replace them as a preventive maintenance measure because of the mileage, replacing them along with spark plugs is a good idea to avoid a possible problem in the near future.
It's completely up to you to take their advice, my advice is to replace those items if they are original for the reasons I have already stated.