I have an iPad 3. Everything was fine until I was forced to update to iOS 6.
You are mistaken. You were NOT forced to update the iPad. You chose to update on your own. You may not have known what you were doing, but that is not Apple's fault and they forced nothing on you.
Since then I've lost apps on my home screen that I can't seem to retrieve the ones ive lost, even looking up the app in the App Store.
Did you swipe from screen to screen to look for the apps? Did you do a Spotlight Search to see if the apps are on the iPad? Did you ever consider syncing with iTunes again order to recover your apps or restore from an iCloud backup in order to restore everything? You do know how to do all of this don't you? Certainly you took the necessary precautions before you updated your iPad didn't you?
down loaded games for my grand kids that no longer play any sound.
You have system sounds muted more than likely. You know how to get unmute system sounds don't you?
If you lose sounds for keyboard clicks, games or other apps, email notifications and other notifications, system sounds may have been muted.
System sounds can be muted and controlled two different ways. The screen lock rotation can be controlled in the same manner as well.
Settings>General>Use Side Switch to: Mute System sounds. If this option is selected, the switch on the side of the iPad above the volume rocker will mute system sounds.
If you choose Lock Screen Rotation, then the switch locks the screen. If the screen is locked, you will see a lock icon in the upper right corner next to the battery indicator gauge.
If you have the side switch set to lock screen rotation then the system sound control is in the task bar. Double tap the home button and in the task bar at the bottom, swipe all the way to the right. The speaker icon is all the way to the left. Tap on it and system sounds will return.
If you have the side switch set to mute system sounds, then the screen lock rotation can be accessed via the task bar in the same manner as described above.
This support article from Apple explains how the side switch works.