The new Google Report system is quite a bit different from the legacy Report Center. If you have any desire to keep your old reports, you should take a look at this video from search engine land blogger Brad Geddes: How To Navigate Google’s New AdWords Reports And Avoid Losing Valuable Data
Making a report from scratch is not so much of an issue. However, recreating a report that you need might. Some data formats have changed (the month field for example) and the method you go about adding fields to the reports is not completely intuitive at first glance.
If you have old reports that you want to keep, I recommend watching the video and then pulling up the new and old AdWords Report tools at the same time. Looking at the old report template will help you figure out where to look for data columns in the new tool.