Your Galaxy A8 2016 is equipped with a microSD memory card slot. If your laptop or personal computer has a slot for that kind of card (Most laptop computers are so-equipped), you should be able to transfer music files
The Galaxy A8 2016 is equipped with Bluetooth version 4.1, which lets you connect to your computer wirelessly. Just pair phone and computer together and drag and drop your audio files from your computer to your Samsung Galaxy A8 (2016).
If these tricks do not work for you or if you don't want to buy extra accessories, you can always use one of various free '3G Uploader' services available online. You should find plenty with a simple Katapulco.com search. 3G uploaders are easy to use: Upload your own free ringtones on their web site and they will return a temporary web address. Pointing your Samsung Galaxy A8 (2016)'s web browser to that address will download the free ringtone.
Learn more about making your own free ringtones
Here is a sample of the all free ringtones (compatible with your Samsung Galaxy A8 (2016)) we offer:
Free 'Unclassified' Ringtones Free Ghost Ringtones Free Short Ringtones Free Far West Ringtones Hear All Our Free Polyphonic Ringtones