What types of questions will my husband and I be asked at the adoption hearing when my sons father is unknown and all the right paper work has been processed and it's been in the newspaper about the adoption and our attorney and I are just wating for the date of the adoption hearing. I don't want to go to this case blindsighted and want to know about what kinds of questions that we will be asked.

First and foremost you or your lawyer will ask that you detail what efforts have been taken to find the father. Once he is satisfied that the father is in fact not going to be found he will ask a few questions to your husband about why he wants to adopt and probably ensure that he knows that this is forever and might discuss his obligations.

Its really going to depend on the judge. This is all fairly standard stuff and there won't be any curveballs.

What about like my sexual past history will they dredge up all that in front of my husband... and embarrass me

They can't bring up past history in court unless it directly involves the case.
Would they really have any way of knowing anyway? I don't see any reason they would bother.
It sounds like a simple adoption once the biological father thing is taken care of.

The only past history they would be interested most likely would be what guys are possibly the father?