Hi there!

I just moved into a new house and the prior owners were big gardener, which is leaving some big shoes to fill (and flowers to nurture). I am a total newbie (only lived in apartments with no yards) and am just starting out, and the most pressing is the yard itself -- it seems like it has been taken over by every type of weed on google! However, there is one type I can't seem to identify, and it is the most pressing issue.

Can anyone help me identify what this plant/weed is? It is growing so tall, so fast, and taking over my yard!(from the picture, i think it looks a little like individual plants are wide/sprawling and flat, but they aren't -- they are tall and slim). (Also, I am not referring to the little white flower things; I did see those in my google search).

(As I said, we just moved in, and have never had a yard, so given that it got this bad in a week, we are having someone come and mow it while we figure out if we are the do-it-yourself type--that is pretty standard for where we live and it seems everyone on our block uses the same landscaper who also lives on our block, so we are doing that too, at least at first, also to build good will).