Hi, i dont know if you solved the problem with your puppy.. Anyway I will tell you what we usually do.
All the time we keep with us something to reward him with. This works in general for anything you want to teach your dog.
Start socializing your dog with your family, friends neighbors,etc. Anyone you have close and wants to help. Ask them to talk to you and ignore her.. Just to let her know she is not in danger or risk. If she runs away.. You just have to keep her on the leash to avoid her running. After a while talking. Ask them to give her some food, or something she likes a lot. She will associate saying hi to humans you talk to, with the reward ; and will keep saying hi just to get the reward..
The reward not always has to be food.. It can be her preferred toy.. A kiss, anything she likes a lot. It is also true that this will change with the time.. So you can start with few pieces of food..(always small pieces, the goal is to train her brain, not to make her full and lose interest on the reward. ) And then move to kisses, scratching her belly or whatever you find out she likes.
Be patient but consistent, they need many repetitions and good mood to learn something.
Our 4 months old basenji already sits, waits on a command, and lays down and we all the time repeat and repeat the training to avoid him to forget.