If you bought the Mac from new you will have phone support from Apple included (I think 30days or so - you can check when you look at the “about my mac”).
general Mac OS guide :
https://support.apple.com/en-gb/guid...lp/welcome/mac
If transferring to external device to attach to mac - if you want to read / write on both Mac and PC then use exFAT format. I’d recommend SSD drives if you want speed - tbh I use local drive combined with iCloud for backup on my Mac - I’ve had external drives fail on me.
This is the recommended route for transferring data from windows to mac:
https://support.apple.com/en-us/HT204087. It does say check you have the latest patches.
I just read this:
Migration Assistant needs something to transfer from; that something can be a Mac, a PC running Windows 7 or later, or a Time Machine backup drive. The source computer can be connected to the same network (via wired Ethernet or Wi-Fi) as the new Mac, or via a direct Ethernet connection between the old and new computers.
You can connect the two computers together via Ethernet cable - copy over the files you want to your Mac - have a read through this article:
https://support.apple.com/en-gb/guid.../13.0/mac/13.0
Try Apple support - they are very helpful- if you are near an Apple Store you could arrange to visit to discuss.
Hope this gives you a few options.