Congratulations on your new bike! As the others have said, regular running shoes will be fine to start off with. After that...a helmet, a saddle bag (attaches under your seat), water bottle, and a flat kit/extra tube should be enough to get you going. I looked at your bike on line and it says it has puncture resistant tires, which is great, but it can't hurt to have an extra tube/flat kit with you. Make sure you carry your ID and cell phone with you, and maybe some cash.
Is there anything in particular you are nervous about? When I started riding i was nervous because I didn't understand the mechanics of my bike and I didn't want to get stranded far away from help if something went wrong. This forum, You Tube videos and your bike shop are great resources. Many bike shops offer basic maint classes, which are very useful for beginners. Good luck and enjoy!