Your question leaves some to be desired. A service company with no assets - odd to say the least.
You should have got a balance sheet when you purchased the company, that tells you how much value there was in each asset or liability.
Create a cash type bank account called owners and deposit the 650K and use owner equity investment as the source account for the deposit
then create each asset account that is on the balance sheet and "buy" that asset from the owners bank account
Anything left over in the owners bank account purchases an asset you create called goodwill.
then create a liability account for the loan, deposit the funds in the owners bank account using that liability account as the source account for the deposit. Then pay out those same funds and use owners equity drawing as the expense for the payment.
the owners bank account should be zero balance, make it inactive in the chart of accounts