Are DNA tests really accurate? I feel like it wouldn't be able to find out who I'm related to or where exactly I come from?

DNA tests are amazingly accurate. I found out about a cousin I never knew I had after she had a DNA test done, and found that of all the people who had also had the test, her closest relative was my father! Turns out her mom was given up for adoption as a baby, and none of us knew about it. The mother, who was white American, married a Korean man, and my cousin was actually hoping to trace her Asian ancestry. But she found us instead. Now I have a wonderful new cousin!

The bit about ethnicities are a little shaky; they can usually pick the main one but the 'smaller bits' not so well. However, matching to relatives absolutely. My top matches were a pair of cousins once removed who I did not even know existed--100 percent verified that they are my relatives.

DNA will indicate what your physical relatives were but what genealogies and names get assigned to which blood groups is where the geneticists can make a change.

They can point you to cousins (as long as they have the DNA of those cousins, of course). When I did a DNA test a few of my already known cousins were identified as cousins, though the 2nd, 3rd, 4th cousinship was not necessarily accurate.

Yes, they are as accurate as the database they have. My husband's DNA test correctly identified two of his first cousins. My DNA test correctly identified several of my second cousins.

DNA is a bit of a delusion

They are extremely accurate in determining whether to people are biologically parent-and-child to eachother.

They do NOT tell you where you are from.

You have 47 independently passed on bundles of DNA. If someone has one (almost) identical to one of yours, you share some ancestry with that person. If you share 23 chromosomes, you are parent and child, or maybe full siblings. If you share almost 23 chromosomes , you are related.

No DNA-company can find cousins or other relatives of yours that it doesn't have in its database yet

I never had one so can't really say

I took one which accurately picked up known ethnicities not obvious from my name, as well as claiming I have 2 Mongol and one Jewish ancestor from 900-1000 years back. Seems logical and likely

Only as good as the data it has.

DNA tests are 99.9% accurate