I'm paranoid, so I kept mine on a premade raw as often as possible up until about a year old and then went to homemade. I used the Vital Essentials and a locally made mix from a butcher. Raw Paws (an online website) also has a pretty well priced premade (muscle, bones, and organ). You'd have to check and see what their shipping would be to you. For some, it's very cheap but for others, not so much.
Aside from that, start with a single protein muscle and bone. Get solid stool. The add in organ slowly. Usually an 80% muscle 10% bone 10% organ (half liver, half other secreting organ) ratio is good to shoot for, but you can adjust it based on your puppy. And then it's variation. I usually start with chicken quarters. Then add in liver slowly. Then start mixing up quarters or wings or necks or frames with various organs. I sometimes get a "whole prey" option (small chickens from a local farmer) that he can break down himself and have all the nutritious organs inside.
When he doing well with the chicken, then choose another meat (pork, for example) and start mixing in small bits slowly over time until he can eat an entire pork meal with no problem. And so on and so on.
There are many many more raw feeding threads on the forum. I would definitely suggest searching raw feeding puppy and you'll end up with a wealth of info! Good luck!