Factory-reset query

I have just got a new iPhone and have transferred over all of the data from my old iPhone to my new one. I want to do a factory-reset on my old iPhone so that I can give it to someone. A bit of background information- I have run out of iCloud storage, so, many of my photos are not backed up to the Cloud. Having said this, my new phone has more storage than my old one (64GB to 128GB). I have also backed up all of my photos to Google Photos (although I don't know how reliable this is).

My question is: If I carry out a factory-reset on my old iPhone, will it change anything on my new phone, e.g. will it delete any photos that weren't backed up to the cloud, even if it is now all on my new phone?

Thank you!