IT’s a GFCI right? It should have a test button that pops the breaker when you push it. In fact, since it had a history of not resetting and now it does it’s important that you DO test it via the button. If pushing the button doesn’t make it trip then you need to have it replaced.
If pushing the button trips the breaker then you can easily determine if any other outlets are also protected by this breaker.
Find a small appliance, lamp or radio that requires a plug to work. Avoid motorized appliances. A small radio works best.
Plug it in to a working outlet and turn it on. Leave it on but unplug it.
Manually trip the bathroom GFCI.
Plug your appliance into outlets that are nearby the bathroom one. Depending on the age of your house, your bathroom one could be protecting other plugs outside or in your kitchen if those plugs are close by.
If you find a plug that doesn’t work, leave your radio plugged into it and then go back to the bathroom GFCI and reset it. If your radio comes on then you found a downstream outlet.
GFCI’s are usually required whenever the outlet can be used to plug in anything that might contact water or the earth. Any plug that is within 10 feet of a water , sewer, outside source should either be a GFCI or a downstream receptacle.
I don’t know your skill level so let me just say that you should have a qualified electrician change any faulty electrical equipment. They might be expensive but they are better than accidental electrocution.