What range on the pH scale is considered very acidic, acidic , and slightly acidic. Also what range is considered very basic, basic, slightly basic.

The numbers are rather arbitrary and I'm sure you can find many who will choose other numbers.

I call pH = 0 and 1 very acidic.
I call pH = 2,3, maybe 4 acidic.
I call pH = 5 and 6 slightly acidic, in fact I call 6 very slightly acidic. You can use that as a guide for basicity.