How do I transfer my data from one Iphone 6 16GB to another Iphone 6 32

Backup the phone that has the data you want to transfer and then restore the other phone from that backup. Note: this requires you to delete the phone prior to restoring it from backup. If you only need certain files you may get by with moving those files to the cloud. If you want to transfer apps, pictures etc. do the backup/restore.