I'd like to depreciate my new computer and phone but cannot find the Asset category. what do I DO?

If you're a W-2 employee, under the Tax Cuts and Jobs Act (TCJA) that Congress signed into law on December 22, 2017, the unreimbursed employee expenses deduction has been suspended in tax years 2018 through 2025.

If you're self-employer (Schedule C), you'll enter the computer assets and phone on the Here's your XXX info screen. 

1. Type Schedule C in the Search box.
2. Select the Jump to link.
   • If this is your first time working in this section: You’ll be asked some questions about your self-employment work and income and then have a chance to enter your expenses.
   • If  you have already entered some information about your self-employment work:
     • Select Edit next to your business and confirm your general business info if asked.
     • Select Add expenses for this work.
3. Select an expense type that you had.
4. Enter your expense description and amount. (We may ask you some additional questions for certain types of expenses.)
5. If you had more than one expense for a type, select Add another group to include them all.
6. If you have additional expenses of other types, repeat steps 3 through 5 above to add more.

If you use TurboTax CD/Download Home Business follow these instructions to enter your expenses.

Source: TurboTax FAQ