Hi,
I recently got my green card approved in 2019. But in 2018, I was in work visa. So, now while filing the tax return for 2018, which form do i need to fill? Is it form 1040 for permanent resident? or because i was non-resident in 2018, i need to submit 1040NR form. Please advise.

You should file one for permanent resident regardless of your status before.

Solu le bhanejhai, yes pali hajur le tax file garda permanent resident status show garera garnuhosh.
$30 tax file garnu hunxa bhane malai dm garnuhosh.