I did this with 23andme years ago. Mostly, I wanted to find out if I had either of the genes that increased risk for Alzheimer's and Parkinson's. I learned that I did not.
I also learned my ancestors were 100% European, mostly northern Europe and Scotland. I had zero Asian, Middle Eastern, Native American, or African ancestors. I was a bit surprised that it was so homogeneous. I had expected at least 1% from some non-Caucasian heritage, but not according to 23andme.
I also learned a few other things before the FDA cracked down on 23andme... like I had no predisposition to male pattern baldness, breast cancer, and a few other conditions.
I got a lot of intra-23andme emails from people who were obviously related and wanted to find out my family tree to see exactly how we were related. I don't care about any of that... but if you do, you'll find long lost distance relatives everywhere.