For tracking code, you only need to set a tracking code on thank-you page on which visitors are directed after completing the transactions. In this code, you need to fill some details. Now, in Analytics, you need to set goal for sale completion, which will provide you information that how many sales you made. Regarding revenue generated by these sales and product sold you can get information in E-commerce option.
For more information about visitor interaction on your site while completing a transaction you can set funnel, which will provide you information that where you are losing your visitors.