The danger to answering something that already knows a lot about you, is that it's just testing you to see if you pose any threat to it or it's trying to otherwise trick/exploit you.

There were lots of Babylon 5 episode where they had to deal with these issues, sometimes just as a hilarious side comment about first contact events.

One species initially tried to pretend that Earth was one of their lost colonys, While also trying to economically exploit the humans.

There was an alien probe that was asking them technical and mathematical questions. However, The probe was designed to find advanced civilizations and then destroy them if they answered correctly.

There was also an incident where super advanced aliens from a different dimension turned out to be genocidal and ultra religious.

It's science fiction, but you can get an idea on the odd possibility's there could be when dealing with first contact. Just because a race is advanced, It does not mean they are going to be friendly or kind.