Much has been written about the enormous importance of looking things up before you write about them so as to avoid ranking too high on the Dan Brown Scale of Did Not Do The Research—but there’s another side to this particular coin. As someone who spends a hell of a lot of time looking stuff up on the internet, I can affirm that it is, in fact, possible to do more research than you can actually use.
There are any number of methodologies for conducting research, but the one I generally end up following to start with, at least, is the Wiki rabbit hole. It’s ill-advised to rely on Wikipedia for all of your information, of course, but it’s a jumping-off point from which you can track down primary sources; it tells you what you need to look up next. It can also lead to some fairly bizarre search strings, and you can come out miles away from where you started, having lost hours, but it’s fun most of the time…except for when it’s frustrating. It is also possible to go too deep, to get hung up on some particular tiny detail that almost certainly isn’t important enough to warrant this level of focus, and find yourself bogged down and going nowhere. There’s a point where you have to pause and back away: you don’t need to get a degree in the subject, you just need to not get specific things hilariously wrong.
Such as physical setting. The original draft of what would become my novel Strange Practice was written before Google Street View existed, and much-younger me hadn’t bothered to look up maps of London in the middle of NaNoWriMo rush, so there were several instances of completely erroneous geography worth at least 7 Dan Browns. When I rewrote it a decade later, I was able to accurately describe the setting and the routes characters would have taken through the city, including the sewers—although I then had to take a lot of those details out again because they did not need to be on the page.