What does find my mean for a MacBook 2015?

My MacBook Pro 2015 was stolen, and I am afraid that my password was not strong so someone can log in. I use Find My and saw it was last seen 2 hours ago, but they were stolen 16 hours ago. On top of it all, I missed to mark it lost until recently. My question is what does it mean if my MacBook Pro was seen 2 hours ago? Does it mean they logged into my MacBook?