In order to log in to Authorize.net, navigate to this URL: https://www.authorize.net/

Choose Sign In, Merchants:

Enter your userid and password:

If you want to change your account details, click on Account, User Profile:

If you want to view transactions, click on transactions:

Authorize.net will hold the transaction for one day in unsettled and then will place it in Settled Transactions. If you want to see settled transactions, pick the date range or select all.