Welcome to the Apple Support Communities!
If you erased and set up your iPhone 7 Plus as a new phone, any apps that originally came with the device and are tied to your Apple ID would be available for download again. Search for the apps first, because they may have been placed in a folder initially.
Use Search on your iPhone, iPad, or iPod touch
Create folders and organize the apps on your iPhone, iPad, or iPod touch
Download your past purchases
Take care.