What we do is treats when ours goes on the pad. When he was very little 6 weeks old, I tried outside also and was not impressed
At night, he has always slept with us however, we put a play pen next to the bed with a pad in it. When he woke up at night or from a nap we put him into the pen until he peed. They will usually pee shortly after they wake up. He got praises or treats when he peed. Now I keep a pad in a place he knows and if I don't take him out right away when he barks he will go to the pad and go. Then he gets a treat. If he has an accident I distract him from the place and then clean it up. Sometimes he will go on the pad just to get a treat and then will come to me to let me know.
It takes a lot of time and patience when they are so young. I hope you enjoy yours as much as we are enjoying ours.