Q: acidic (about food) と sour (about food) はどう違いますか?
A: People can absolutely eat acidic things. You're probably thinking of something like hydrochloric acid or sulphuric acid, which are harmful, and people obviously can't eat.

But there are many types of edible acid:
citric acid is in citrus
tartaric acid is used in baking
malic acid is in apples
lactic acid is in cheese

Vinegar is probably the most acidic food that people eat regularly.
Q: acidic と sour はどう違いますか?
A: “Sour” is a taste whereas “acidic” is more technical and describes the chemistry behind sourness.

If you tasted lemon juice, you would say it is sour. Sometimes “acidic” is used when describing wine, but that is usually because wine tasting is more technical and sophisticated.
Q: acidic と sour はどう違いますか?
A: Acidic has a really negative feeling associated with it, since acids chemically break down and sometimes burn things they touch.

For example,
Soda is an acidic drink that breaks down the enamel of your teeth.

Sour usually describes the flavor of a food. Imagine candy, usually something sweet and tasty, and then think of the opposite taste. Think of something like a grapefruit. That's what sour is.