I'd be a bit cautious for lots of reasons.
My in-laws are big into genealogy and did I think the ancestry one a number of years ago. It wasn't actually very interesting and there are questions about how accurate they are. They found the 'what countries your background is from' stuff fairly generic, some of it didn't line up with what they knew from their own research so they were a bit disappointed.
Then there's the risk of what you could find out. I would have said, say ten years ago, that we had no skeletons in our family closet either.
But things that have since come out that could have come out in a more shocking way via a DNA service:
1)A secret half-sibling nobody knew about, the result of a 'shameful' teenage relationship
2) A recessive hereditary gene that had gone unnoticed for generations till someone unfortunately married and had kids with someone with the same v rare recessive hereditary gene. Probably good to know, but its not the best way to discover significant health news.
You may feel confident in your own generation, but if you discovered, say, your parent had a half-sibling who had been given up for adoption, or your DD discovered that, what would you do? Also, with 23andme, they test for a LOT of health conditions. I didn't used to think my family history had any, except a tendency to high cholesterol, until a family member was diagnosed with Parkinson's and another with lewy body dementia, which are linked. I considered doing a 23andme a few years ago, before having kids, then I reflected on whether I'd actually WANT to know if I carried the Parkinsons gene, which I well might.
It could all be a lot for a17/ 18 year old, so I'd be very, very careful to understand exactly what each service will provide to you, and think through what you'd want to see happen in different scenarios. I'd be inclined to stay away from the health ones, and even the others I'd think very carefully. They might not be 'your' secrets but discovering, say, your favourite auntie had a lovechild they gave up for adoption isn't the kind of thing you can un-learn.