Any of those are possible.

Frist trip the breaker off and on. A breaker can trip, but the handle not move enough to clearly indicate that it tripped.

But you will feel the difference when you move to the off position.

After a tripped breaker the most likely cause is a bad connection at a receptacle if they used the pushin connections on the back of some cheap receptacle rather thanthe screw terminals.

With the breaker off start check the FIRST receptacle in the circuit. Typically the one closes to the panel, but not always.

To do more testing you need some kind of test equipment.

The $1.79 neon test light is good for most problems.