Mining Litecoin with a GPU is like trying to fill an empty swimming pool with a tea spoon
. It can be done, but it makes no sense when there are specialized gear for that. (scrypt ASICs)
Several years ago when LTC GPU mining was profitable people got 500-800 kh/s out of a powerful desktop AMD GPU so 500 kh/s sounds about right for a new laptop nvidia GPU.
You might want to try mining ZCash with EWBF miner or some another coin which is profitable. Or just take the easy route and use Nicehash miner which automatically chooses the most profitable coin for you after benchmarking your machine. Mining with a laptop isn't smart though. You might fry it as it isn't designed for long term high gpu loads.