Do you get sound from BT earphones? How about if you connect it to an audio system through an AUX input? If the first one works but not the second, your headphone jack might be damaged/disconnected. If the second works, maybe your headphones are damaged or have the wrong impedance (some phones don't like extra-long cables or poor-quality ones).
If yo don't get sound from BT earphones, then it might be something wrong with audio processing in general.
Have you tried checking if you get sound in Safe Mode? If you do, then it's an app or a glitch in the system that's keeping the audio from being sent out.
And lastly I'd test if the phone detects the earphones. Usually, if you're playing audio through the speakers and then connect earphones, audio should stop on the speakers or at least see a change in volume level (to protect your ears from lound sudden sounds).