Cannot empty trash

Why are you using Secure Empty Trash? Are you aware that it will take an extremely long time to delete 3500 items? Why not simply Empty Trash?

When I purchased my laptop I got the floor model.

If it's still new and you haven't really started using it yet, you'd be wise to erase the hard drive and reinstall the system from scratch. You have no way of knowing what some doofus did to it while it was sitting out for people to play with. It's not outside the realms of possibility that somebody installed some kind of keylogger or something from a flash drive, hoping the machine would end up in someone's home. A more mundane possibility is that somebody who didn't know what they were doing fooled around and messed something up.

If you've already done that and are still having problems, are you using an admin account? What's in the trash (in general)?

Open Finder preferences, click on the Advanced icon in the toolbar, uncheck the Secure Empty Trash option. Now select Empty Trash from the Finder menu or CTRL- or RIGHT-click on the Trash and select Empty from the contextual menu.

I haven't done that yet, but I would like to avoid doing that because I have alot of photos and would have to back them up before.

You must back them up regardless, especially given the undetermined state of your machine, unless you're okay with losing them. Data loss can happen any time, even on a brand-new machine, and does not wait until after you've had a chance to get backups made.

As to the problem, I see Kappy has solved it for you.