You need SharePoint Designer. If you have not used it before, it may be a bit daunting. Here are the general steps:
Open the site with SharePoint Designer, then open the list. In the Settings page, find the panel for the Workflows and add a new workflow.
Edit the workflow and add an action that sets a field's value. You may need a few steps to extract the year from the created date and store it in a variable. SPD is not great on text manipulation functions, but it can be done by writing the date to a variable as an ISO format date and then taking the first four characters in a separate step. The variables and the ID can be concatenated with the String builder and written to the final destination column.
Take little steps, one by one, publish the workflow and run it manually on an item.
When you are happy with the workflow, set the workflow to start when an item is created and publish again.
Here is a good video to get you started. http://sharepoint-videos.com/module-1/sp10creating-a-workflow-on-a-list-using-sharepoint-designer-2010/