Business insurance should go under which category?

It should go in an expense category called "Insurance" or similar.  Personally, I always organize my Chart of Accounts with a header account called Insurance, and then I make sub-accounts underneath it for all the different types of Insurance, i.e. Automobile Insurance, Property Insurance, Liabilty Insurance, Owner Insurance, etc.  These will all roll up the total into the header account called Insurance, but makes it easier to see at a glance what each sub account total is as well.  This is strictly a preference.  I'm sure that many (most) use just one single account called Insurance.

Also, a good practice for Insurance costs (when you pay a lump sum total for an entire year up front), is to initially post the entire amount to an asset account called 'Prepaid Expenses'.  Then you make a JE to repeat each month for the total / 12 months and CR the Prepaid Expenses account, and DR the Insurance Expense account.  This gives you a more accurate monthly P & L and Balance Sheet because it amortizes the expense over the entire period, instead of having a big hit against Insurance Expense all at once.

This goes for all larger lump-sum payments made for other types of expenses as well, i.e. Property Tax, Software Maint/Subscriptions, etc.  I do the same for the asset account as I do for the expense; create a header account called 'Prepaid Expenses' and then sub-accounts for each type of prepaid expense under it.

Hope this helps.  Good luck!