Hi angie and welcome! Well done on your first day. The first few days can be challenging until you get into ketosis as you may have cravings or feel hungry. This is normal. Drink water, tea, coffee, and if all else fails have an early night! Just do whatever it takes to get to the ketosis part and then it gets 100% easier!
Also, fear and excitement can be two sides of the same coin... Try to be excited more than fearful if you can. You will find loads of support here, and you're doing a fantastic thing for yourself in taking the weight off.
You only ever have to get through today! You have done that already - you can do this!!!