Open the terminal and type
alsamixer.
Use the arrow keys to hover over each column and raise up the Master, PCM and etc.
Look at the bottom of each column to see if it's muted or not.
{mm} means that it's muted and {00} means that it's unmuted. Press the m key to unmute each column if you have to.
If that doesn't work try installing pavucontrol-
That will give you more control over sound. <OR> at least it should.
https://packages.debian.org/search?keywords=pavucontrol
Running the command
aplay -l will show what sound card you have.
My Sound Card disabled by default.
