My speaker is not working how do I fix it.

I dont know if this model has bluetooth but if it does, its possibly connecting to a headset or something like that causing the sound to go to the headset. If you use the headphone jack you might try inserting the jack and removing it a few times to see if something got stuck inside the tablet making the tablet think there are headphones plugged in. another thing you can try is rebooting the tablet. not sure how you do that on that tablet but its probably something like holding the power button until it shuts off or gives you the option to reboot.