If you can access the files you need, just use a Wi-Fi file app like Wi-Fi File Explorer to browse your old phone's files and download the ones you want or ES File Explorer to transfer files via NFC or other methods.
I definitely recommend using Google as your Contacts and Calendar account so you can access them on any of your devices (they sync the changes), even iOS devices, as well as any Web browser when you're logged into Google. You can use Outlook on your PC with Google Calendar, too, and I assume also your contacts (I don't use Outlook, but had to set up the Google Calendar for a family member on their computer). I don't use the Samsung account or phone-only option (is that still an option?), though the Samsung account will sync between your devices, too.
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