Parent has passed, what do I do?

Location: Indiana

I’m posting here hoping to get some guidance, because I genuinely have no experience with this and was never prepared for it.

My parent passed away unexpectedly. He left behind a business, several homes, and what we believe is a will/estate/trust funds for my siblings. Everything seems straightforward, except we don't have access to anything or anyone.

My parents partner, who has access to almost all the paperwork, has yet to submit anything to probate. We were denied access to the will and there has been no death certificate. While looking for my parent's lawyer or the person that set this up, we found that he is also deceased. Because my parent was such a huge part of our lives financially, we were reassured that he hasn't left us "unprotected," but everything seems to be secretive or unclear. My parent's partner has mentioned getting an attorney as they don't seem to understand it.

I've been told that these things can take weeks to months after death?

Then again:

• There is no death certificate
• Probate can't start, due to no submission
• We have no access to the will
• The person that set this up is also deceased
• We are heavily relying on my father's partners words

Genuinely , I am asking:

• Should I get my own attorney or is now not the time?
• Is any of this alarming?
• Is there anything I need to look out for?