Deductions & credits

Follow these steps:

1. Please go to federal income. 
2. Locate your business, 
3. Edit/review/update/revisit. 
4. Business summary screen shows, edit the business. 
5. Continue, continue, continue, 
6. NEC yes/no, NISC yes/no, 1099-K yes/no, income, 
7. keep continuing until you get to Business Income and Expenses showing  the home office location that @KrisD15 showed above.
8. Edit/start/review/revisit
9. Office name
10. Tell us more
11. How big - this is where you enter the actual office space and entire home to get the correct percentage  for later calculations.
12. continue
13. when did you start, how many months
14. continue
15. how do you want to enter home office expenses? If you take simplified, you won't enter any expenses. If you choose actual expenses, you can enter all the things you mentioned. 
16. begin entering items as the program asks