You'll have to click on the 'Games' section, second down on the list. Clicking on that will link you to all subsections, everything from what's new in the store down to Vita and the classics. There's an entire area for PlayStation 2 and PlayStation games, but you'll have to spend a decent amount of time getting used to the location of everything around the store.
The way the PlayStation Store was setup beforehand with a folder for every single thing has disappeared. Browsing the store now, there are more items combined to make it easier you might say for some people, depending on how you look at it.
For instance, if you're looking to grab trailers from the store from their newly released folder section now you'll have to head to the 'Media' link where along with trailers there are also apps in there if I'm not mistaken (I'm basing this all on memory). The thing is though that it's going to take awhile to get used to where the store's entirety becomes familiar enough to each user.