I am also a new owner and had to figure this stuff out.
I found three good ways to move files.
1) Plug in the USB cable and copy using Windows file explorer or command line. The phone mounts like a USB flash drive. Detach it from the PC before you unplug it.
2) Turn on WiFi, go into the Files application on the phone, and connect to a shared directory on a PC. This lets you use the phone's file management interface to copy files either way.
3) Load SwiFTP onto the phone, turn on WiFI, start SwiFTP, and then you can FTP into the phone using a PC FTP program (so you can use the PC user interface rather than phone to move files.) If you use SwiFTP, turn it off when you are not using it to save battery.
Photos and videos show up in /DCIM/Camera.
Make a ringtones directory, put your MP3 or WAV in it, and from the Music application on the phone, find the sound and choose Use as Notification Tone (to add it to the tones list) or Use as Phone Ringtone (to make it your active ringtone.) The sound should now show up for selection as a tone. I got a custom SMS alert this way.
Mike