How would you journalize this:

Sold woodworking machinery and supplies to a company on account, for $24, 850.

I know you would do

Cash
Sales

But I know you need to decrease inventory... but I'm not sure what else... please help!

I meant Accounts Receivable(debit) and Sales (Credit).

Debit Cost of Goods Sold for the cost. So your 2nd entry is dr to COGS and cr to Inventory. (Though I don't see where a cost is presented. Are you sure you're doing perpetual?)