Commercial raw has everything a dog needs. It has been prepared so that all nutrients are in it and you don't have to feed anything else. If you do it yourself you have to find out yourself what is needed and then buy it all, in some cases you can't get it from one place.
When starting to feed raw that you make yourself my advice is to buy a book and study that one way of raw feeding. If you deside only to ask from other raw feeders in the beginning you will find out that there is quite a lot of ways to do it and that can be confusing too.