1099 and WFH Deductions

Hi, I became a 1099 contractor mid-year this year and have been making quarterly estimated payments. Since I don't want to accidentally owe taxes, I have not been taking deductions into account when I made those payments.

 

I have some questions about what year-end deductions I am eligible for and how to report them comes April.

 

1) How do I know if I am eligible for QBI deductions? I am working as a 1099 independent contractor researcher through a vendor company that does my billing for my client, but I am not considered an employee of the vendor company. Do I still qualify as a sole proprietor? 

 

2) What are the documentations that  I need to provide for WFH deductions? (rent corresponding to the office space, internet expenses) Do I provide these at the time of filing or only in the case of audit? Can I file these deductions on turbotax?

 

Thanks!