IMO the best overall case for the Note 8 for screen protection and covering the ports is the Otterbox Defender. You can get it cheaper at Sam's, Wal-Mart and Amazon, or you can go on Amazon and buy one of the clones that a number of makers sell that will run only about $12- $15 but it's basically the same if money is tight.
I might order one of the Clones sometime just to see what it's like. I had a clone for the S7 and it was pretty darn good.