Unfiled partnership LLC taxes (2019–2022), dissolved LLC, small income. What’s the least painful way to fix this?

I’m trying to clean up a tax situation for a small LLC and could use some guidance on the best way to move forward.

-LLC started in 2019, taxed as a partnership
-Only tax return ever filed was for 2023
-2019–2022 returns were never filed
Business had very minimal income/expenses most years (was active, but barely)
-We recently dissolved the LLC at the state level and are shutting everything down
-We received an IRS bill for 2023 but misplaced it and haven’t responded yet
-We do have access to bank records for all years

Main questions:

-What’s the correct order of operations here? File all missing partnership returns first before contacting the IRS?
-Should we call the IRS now to see what they show as owed, or wait until we file everything?
-Are there penalty relief options (first-time abatement, reasonable cause, etc.) for a small/inactive business like this?
-Since it was a partnership, how much risk is there of penalties per partner for late filing even if income was low?
-Is this something we can realistically fix ourselves using software, or is it worth hiring a CPA/EA given the situation?
-Anything specific we should do since the LLC is already dissolved?

We are idiots, we know. Thanks for any help.