I am not an electrician (clearly). I recently replaced a lightbulb and a few days later I realized that the light was out, along with a couple of others that I assume are on the same breaker. I checked breakers, nothing. I checked bulbs, nothing. I live in an older home without ground thus no GFI's. Does anyone have any solutions?

So did you confirm that this bulb was good by placing it in another fixture elsewhere? You may have a n open circuit, one where a common wire either hot or neutal has come undone and you no longer have a complete circuit. Do you have a tester and know how to use it?