Hi and welcome to COL! (by the way photos of your lovely fur bundle are compulsory)
There are many good foods on the market, but I believe that Pedigree Chum is not one of the best evidenced by the consistency of poo's - of which you will soon become and expert at.
I am owned by Jinley, a 2 year old little orange roan girl, who is now raw fed. However she loves Eden dry food as well, but not sure if they do a puppy range and is only available online unless you are lucky.
There are a few complete foods on the market which are used here, Arden Grange, Burns to name but two. They all have different effects on different puppies and what suits one does not always suit another, so much of it is trial and error unfortunately. If you have a local Pets at Home, you could ask for some food samples. Personally I would always make sure it had a high protein content with only a small amount of cereals and always suitable for a growing puppy.
You will get plenty of advice on here soon.
Did I mention photos?
Pat