Welcome to DTA, I'm sure you'll get lots of ideas for more tricks on here.
Do be careful with your pup for a few weeks, you see he's very very young to have left his mum and siblings and you're going to have to make that up to him with good feeding and lots of cuddles. It also means that later on you might have to work extra hard with his socialisation too. But if you stick around DTA and ask questions you'll get loads of help and encouragement from other people on here who know lots more than me .
I love GSD/lab crosses so I hope you post lots of pictures of him as he grows up, I'm sure you'll have great fun with him... and I hope your cat comes back!
Welcome! Sorry about your cat, mine ran away for over a month and then came back after we moved. Your puppy is so cuute. I have a GSD and my mum has Labs. Youll get lots of helpful info from here about bringing up a pup. Enjoy.