Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
It depends upon what site you are choosing items from and wish to buy from. If Amazon.com, you would click on the
icon at upper right (that ought to show (2) for the two items selected, then click on the yellow
Proceed to Checkout
button at the upper right. for other websites, clicking on the Shopping Cart (or, cart count) indicator or icon should take you to a screen with a similar 'Buy' or 'Checkout' option, or button.
But tell me the specific name of the website, and I will give you specific instructions for that website.
(If this answers your question adequately already, please rate my Answer, so that this case may be closed. Thanks.)