How do I backup itunes

I am having so many issues. My notes just disappeared?! I never deleted went iCloud I had them being backed up and not there?

why can my provider chose to download my notes? I read and read but in the process I have learned so much in these past 2 days about iPhone/icloud/family sharing as I now have 2 iPads and my iPhone and a pc. But my iTune(per instructions) are downloaded on my iPad not ALL went to my iPhone and on top of that my play lists that I created are gone?! I need my music backed up. I’m old and really cranky right now. I remember when iPhones were the “easy choice.” I miss my blackberry. I digress, I need to backup my music/itunes. Help