Your Y3 2018 has a microSD memory card slot. If your personal computer has a slot for that card type (Most laptops are so-equipped), you should be able to save a music file
The Huawei Y3 (2018) 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
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