The most important thing to do is make sure your building's grounding system is set up properly. In a lot of older buildings, it's common for the ground system to need some maintenance.
First of all, you should check what your ground system ultimately connects to, which should be some combination of ground rods, embedded concrete grounding (also known as ufer grounds, where you clamp a ground wire to the concrete rebar), and water pipes. Modern electrical code calls for either a ufer ground (best, if you have it) or two ground rods at least 8 ft long, hammered into the ground at least 6 feet apart from each other. Older electrical codes sometimes allowed connecting to water pipes only, which is no longer allowed. Back when pretty much all pipes were metal, the incoming cold water pipe was a great ground source, but now that many pipes have been replaced with plastic (or could be at any time by the city), they no longer work so well. If there's any doubt, it never hurts to add a ground rod -- dirt is a terrible conductor, so you really want as much contact with it as possible.
If you have enough expensive equipment to justify the cost, it's possible to test your grounding system's resistance to the earth. It's rarely done in residential settings though because usually it's cheaper to just add another ground rod.
Additionally, you should double check that your neutral-ground bond is solid and not corroded or anything. That's important in case the lightning hits your hot or neutral wires.
Finally, make sure everything that needs to be grounded is connected to the grounding system. That includes things like coaxial cables for antennas and cable, your plumbing system if it's not plastic, and your phone lines if you still have a landline connection (even if you never use it).
That should be sufficient to make sure a lightning strike won't cause a fire. To attempt to also have it not damage anything, you should also add some surge protection, ideally the whole-home kind that attaches to the breaker panel.
