Creating a program to purchase instantly

Hi, I am a college student and have a couple questions. This is nothing related to school, nor am I in any way savvy when it comes to this.

I am looking for tips/suggestions or physical help on creating a program that can do a few things...
- access a link as it is randomly sent out online
-with that link be able to purchase that product with the appropriate information already "embedded" in the program

My intention is to buy something as the link online is released (since it is first come, first reserve products) I need to do this on a more efficient route.

if this does not make sense, please feel free to ask away! I can go further in depth which may help out. I would greatly appreciate the feedback!

thanks!