I am the sole heir to my mother's estate;opened an estate acct. My question is what do I do with the money in that acct? Can I use it to pays bills such as home owners insurance,etc.

Yes.

Assuming the home owners insurance is for your mother's house.

You can use the money to pay for any debts that her estate is incurring.

You can pay any expense that is part of your mothers estate.

Hi,
If you are the Executor of the estate, I highly recommend getting a lawyer, and/or a CPA to give you some Professional advice. Best wishes.