I've done everything else I need to do. I just need to "Obtain a blue building password" but I don't know how

I believe it's from a random event. There's not really anything you can do the trigger it, unfortunately.

Specifically, I believe it's a random event that you can only get by refreshing on the blue building page. You don't need to actually know the password to get in, you just need the RE and it will automatically complete that step for you. So you can just refresh there a bunch and you should get it eventually. I think it can still take some time though, so you may need to refresh for a while and then take a break and go back again later or something.

Exactly

Here I am with just forum posts left to unlock the BB and I didn't know about the password. God dang, thank you guys for the heads up