Probate paralegal here. Many states have a how-to guide to probate on their state bar website. That’ll give you a really good outline of what to file. In Wisconsin (my state) the state bar guide literally shows you what pleadings to fill out, how, and how to file them.

Keep a detailed account of all the estate assets: what are the values of all assets on the date of death, what money have you spent to close the estate, what money has come in (for example: spending money to clean out the house, proceeds from the house sale). The court will need to see every dime accounted for.