I accidentally did I cloud on my new phone instead of transferring

Do you still have your old phone? If so go to Settings under General and under Transfer or Reset iPhone then click Prepare for New iPhone and set it up. Then put the two phones near each other and let them sync together and transfer the data. Keep in mind this will take a long time. You can also restore from an iCloud backup there are Apple support articles on this. See if my advice helps.

Reset the new phone back to factory settings→Restore your iOS device to factory settings - Apple Support. You can then start the transfer over again.