Yep it’s true. A quick replacement of the drain has turned into a replacement of much more. However that’s all fine and good and almost done! Just a small leak left and I have no idea how to stop it. It’s down on that U thing as it’s going up and joining to the next pipe. That’s plumber talk there. 
I guess it’s off to the next hardware store to see what kind of suggestions they have. I already put in a new rubber washer thing so I don’t know what’s wrong. Oh and it’s supposed to be hand tightened and that didn’t work. Neither did tighter or looser. So I don’t think that’s the issue. Must be the rubber washer.
Hello. That “u thing” is a j bend and usually a rubber washer will turn the trick for a small leak. Even easier is to make sure it is good and dry and wrap some electrical tape around it. Not as good as fixing the leak properly but still useful and effective.