Your profile indicates that you asked your question from within TurboTax Self Employed Online. This is the correct product if your business is either a sole proprietorship or a single-member LLC, as either files on Schedule C (Form 1040). However, if your business had not yet commenced operations as of December 31, 2018, and had no income, there is nothing to file.
If you had start up expenses incurred and paid in 2018, the general rule is that business startup expenses are deductible in the year when active trade or business begins. Since you had no income-generating events in 2018, your startup expenses will become deductible in 2019, when your new business begins to generate revenue. Please see IRS Pub. 535 Business Expenses for more information.
Also, you must distinguish between startup expenses (licenses, permits, legal fees, pre-opening advertising, etc.) and the amount spent on business assets (machines, equipment, vehicles, etc.). These assets are depreciable over their useful life, although in many cases can be expensed in the first year put in service under Section 179 of the Internal Revenue Code.
If your business is any other type of entity, you will want to use TurboTax Business, which is a Windows only, CD/download product. But this would be next year, when you have income and a filing requirement.