I have only limited experience but I think the worst thing you can do when taking over an startup (with the intention to continue it) is to start with firing people. I know it's expensive and not always viable but you should try to "let it operate like normally" while auditing it before starting firing people.

Like some especially stupid examples:

- firing the main tech lead which had worked month of unpaid overtime (not for month, but the accumulated equivalent of month of work) because he supposedly didn't work enough during the insolvency proceeding/first week after it.

- cutting the cost of renting the storage system with essential data without making backups

- firing most people which where important for the main product

- firing people in such a bad way that most of the rest quit, too

- deciding it's more important to keep marketing people then people from the development team in a situation where the insolvent company had multiple bigish contracts they just where missing a few month of work to be able to deliver to and interests from other customers and the buyer being the main potential customer buying the company to get the product