These don't need to be purchased until you've actually sold your product. You should look into prices though, to get a rough idea on the cost. You should open a business checking account sooner or later to keep all of your business transactions separate from your personal finances. It is important to have your business name on your checks to keep a professional image. You should open this account once you have chosen a name and registered your new business.
Most people can probably get by without purchasing any office equipment at all.
I started on the kitchen table. The point is, don't go out and buy anything until you absolutely need it. If you don't already have a printer connected to your pc, you should think about getting one. You'll eventually need to print a letter to a customer or envelopes or even sales literature. Although you don't need to have one right away, consider the time it will save you in the long run.