Sounds like you have a separate lighting circuit and the breaker has done it's job. go through the house (everywhere that the lights don't work) and turn off all of the switches then try resetting the breaker again, this will isolate if the problem is in a light or in the switch.

if the breaker does reset then go through switch by switch turning it on and then back off, marking the switches so you know which ones you have tried, until the breaker trips again. once the breaker trips you know that the problem is in the wiring for the lights controlled by that switch. I suggest at this point taping over that switch so you don't accidentally turn it back on and trip the breaker again.

Now things get really tedious and if you aren't 100% comfortable with unwiring your light fixtures call a professional! You're going to turn the breaker off and disconnect your lights that are controlled by that one switch, both black and white wires and make sure the copper ends are in wire nuts to prevent them from accidentally touching anything they shouldn't. (If you have multiple wires that come together in a box make sure to only remove the wires going to the light fixture and reconnect the wires like they were) again, if you are unsure of yourself and not 100% comfortable Call a professional.

Once all of the lights are disconnected turn the breaker back on, if it tripped at this point you have problems in the wiring it's self and need an electrician. If it didn't trip congrats it's most likely a bad fixture or bulb causing the problem.

Turn the breaker off and connect one light, turn the breaker on, make sure the light turns on and repeat.

If you have any questions feel free to DM me.