What breed is he, how old is he and what's his history?
In your shoes I would find a good, positive, reward-based training class (check the APDT website for classes near you). Go along without the dog to watch first and check that the dogs/owners look happy and relaxed, that there is no use of rattle bottles/water sprays and that choke chains aren't in use (if any aversives, run for the hills!). Also, make sure they don't spout 'pack leader' nonsense. To quote the late great John Fisher, you can eat before your dog or sit in his bed if you like, but it will mean jack to your dog!! All being well, take him along to the class - many run on a 6 week basis initially, and they're pretty cheap.
He sounds like a slightly unruly boy who needs to learn manners. This will take a little patience and consistency, and is about finding the right reward to motivate him.
When he jumps up, turn your back to him and fold your arms. If he keeps jumping then you can (wordlessly and not crossly) put him in a different room for a very short time out. If you and your OH do this every time (and watch for him with your DS and manage this too) he'll soon get the idea that he gets the best attention when he has all four feet on the floor.
With regards to DS's toys, the are probably more exciting than his own because he gets a reaction when he takes one! You need to make sure you play with him with his own toys so they have a value to him, and teach a strong 'leave' command. You can also teach him a swap command for when he has something you don't want him to have. (I use 'leave' for something not yet possessed and 'drop' for something already in the mouth.) I was just trying to find the video on youtube of Victoria Stilwell teaching leave it, as she does this very well and simply, but I've run out of time. Do have a look for this. If you don't have any luck I'll post some instructions for you later, but it's easier to see it in action!
Good luck, and don't feel too down. I suspect most people here who have taken on a dog have had that 'oh what have we done?' moment!! With patience and training it will pass, and you'll have a brilliant companion 