If the Sound System Preferences are showing the internal speakers as an option, then make sure the speakers are not muted and make sure to try raising the speaker volume using either the keyboard controls, Sound System Preferences audio options settings, or the speaker icon on the menu bar.
Make sure nothing is connected or stuck in the headphone port on the laptop.
If you still get no sound, try connecting headphones or external speakers to see if you get any sound through them.
If headphones or external speakers work, then try playing some audio. While the audio is playing, look into the headhpone jack on the laptop. Do you see a red light?
Try rebooting the laptop. Sometimes a simple reboot will fix things.
Try a PRAM Reset making sure to hold the PRAM Reset for at least three chimes if possible.....if this is a laptop with USB-C ports, then it may be only possible to hold the reset for two chimes.....with a 2018+ model sometimes only a single chime. Do you hear a chime during the PRAM Reset? If not, either the PRAM Reset was not performed properly, or you have some sort of hardware issue with the laptop.