First fix the more serious issue, which is the p0068. Without an advanced scanner to check actual data, all you can do is parts shotgun it. The throttle pedal position sensor should be replaced first, as suggested, since it is the least expensive. Clear the codes and if that doesn't fix it, then the throttle body itself should be replaced. Either the motor or the sensor inside, which are not replaceable individually, may have failed. |Given the high cost of a new one, you could try using one from a yard. These are not a high failure part.
After that, we can look at the MAF code, which may disappear after fixing the first issue.