Hi tmarxmiller,
Thanks for coming to Apple Support Communities for help today syncing bookmarks to your iPhone XR.
You are correct that you can use iCloud. Just be sure you use the same Apple ID on all your devices.
This article is about troubleshooting issues, but will help you find where to turn this on: If your iCloud or Safari bookmarks aren’t syncing
iPhone: Tap Settings > [your name] > iCloud and make sure that Safari is turned on.
Mac: Choose Apple menu > System Preferences. If you're using macOS Catalina, click Apple ID. Click iCloud, then select Safari.
This article will help you understand iCloud further as well: Change your iCloud settings.
Have a fantastic day!