A warm welcome to Mac-Forums.
May I endorse the advice of Moderator vansmith, most particularly in relation to iCloud. The advantage of the latter is that, if & when you choose to do so, you can also sync Contacts, Mail, Safari, Notes and others with your iPhone and to any other iDevices or Macs signed into iCloud using your Apple ID.
Having an Apple ID is extraordinarily useful for everything to do with Macs and other Apple products, allowing purchases, use of iTunes, iBooks etc.
This article will help you to create an Apple ID or, if you have one, how best to use it:
https://support.apple.com/en-gb/HT203993
Ian