Hey friend. What kind of files do you want to sync between iPhone and iPad? Let's say, if you're planning to sync music from iPhone to iPad, you can simply rely on iTunes.
Please note that if you have hundreds of thousands of songs in iTunes Music Library, you'd better create a separate playlist for the songs you want to transfer. Then you can choose the playlist when you sync music to iPad with iTunes. The following guidance will show you how to transfer songs from iPhone to iPad with iTunes.
1. Transfer Purchased songs from iPhone to iTunes Music Library.
2. Connect iPad to computer with USB cable.
3. Click the iPad icon and choose Music.
4. Check Sync Music, and choose the iPhone music playlist.
5. Click Sync at the right bottom.
3 Ways to Transfer Music from iPhone to iPad