Your Asus Zenfone 3-S Max has a microSD memory card reader. If your personal computer can also read that card type (Most laptops are so-equipped), you should be able to save a music file
The Asus Zenfone 3s Max is an Android phone and there are plenty of free ringtone apps such as MP3 Cutter, RingDroid (open source) and more.
More on free ringtones
Here are some of the 100% free ringtones (Asus Zenfone 3s Max-compatible) offered here at MartinsRingtones.com:
Free 'Unclassified' Ringtones Free Ghost Ringtones Free Ringtones-a-gogo Free Techno Ringtones Listen To All Our Free Polyphonic Ringtones