How long does it take to upload all files from iCloud onto my new iPhone?

Apaert from what is given below it should take between 30-45 mins. Depends on the internet speed also.

Apps don't transfer from iPhone to iPhone, only the app data along with app links to the App Store gets transferred.

Apps & Settings --> Apart from the Apps following will also not get transferred.

1. Content from the iTunes and App Stores or PDFs downloaded directly to Apple Books
2. Content synced from iTunes, like imported MP3s or CDs, videos, books, and photos
3. Data already stored in iCloud, like iCloud Photos, iMessages, and text (SMS) and multimedia (MMS) messages
4. Face ID or Touch ID settings
5. Apple Pay information and settings
6. Apple Mail data
7. Apple Music

It all depends on the speed of your Internet connection supplied by your Internet Service Provider.

Remember that "download" speeds are going to be much faster than "upload" speeds, and you will be "uploading" data to iCloud.

Log onto www.speedtest.net and report on the download and upload speeds that you are obtaining. Then.....we'll be able to to make a better guess on how long the upload process to iCloud might take.