Help with Capital Gains TaX

hI,

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Just doing my 2020 taxes and I am waiting for my tax information from my broker. I made around 18k from August to December. When I do my turbo tax it says if I want to use my 2019 income I didn't make any capital gains in 2019 so can I go ahead and submit my turbo tax or wait till my 2020 tax information comes out? A bit confused. And will I be able to for now just omit my capital gains from 2020 if I can just use my 2019 tax information?