Hey tibia,
I'm happy to see youre interest in every aspect of your new dog!

I hope the arrival is awesome!
As far as food, its really whatever you think it good to try, based on brand preference, and usually price!
I started my own dog on Eukanuba large breed puppy food and it was really good - he grew very well, and it gives easy suggestions for how much to feed them at each age in weeks. Once mine got older I swapped him to Pedigree because I couldnt afford to keep feeding Eukanuba! :s But, he kept putting on weight in a good manner, and his coat looked great!
The truth is, most commercial diets are balanced enough for good performance on any of them. There are specialty brands (Hills does a range of specific aimed diets, and my university is a big advocate of Hills, I know a lot of dogs who do well on them) as well as breed specific brands - but I havent heard any super convincing evidence that these breed specific diets are any better necessarily.
So really, its word of mouth and your own opinion. In the few cases of food allergies, there are plenty of options you can try later. The same goes for cases where your dog might not put weight on like you want, or if the diet gives him bulky poos or something - its mostly trial and error to find something that works
Hope that helps, I wouldn't stress too much, just find one that appeals and give it a go!