How can I apply for a job at this specific Little Caesers? I'm 16 and need a part-time job urgently.

Apply online then go into the store and introduce your self to the manager, let them know you have applied. Be sure to try and go when they are not very busy so that the manager can take time to talk to you

Most places have their hiring info online too. Check their website.

I would go into the location. The phones tend to not be answered or come up disconnected. Management is pretty cool and they are always hiring. I believe you apply online though.