How do I add friends through the steam version?

Trying to get my boyfriend and some other friends added to my friends list so we can all play together how would I go about doing that so we are in the same session.

We are all on the same ship but we've been placed in different instances and we're not sure how to add one another as friends.

Any help would be appreciated.

You can get yourselves to the same block via the block teleporters (they are in various places, like on either side of the counters in the Gate area). Additionally, you can look up each other's PlayerIDs via the Visiphone (the purple console) and send the Friend Request from there.