"She reads the newspaper."
Translation:Sie liest die Zeitung.
I'd say it's a combination of constant exposure & patience. from what I've gathered, the articles are learned on a word-to-word basis, & from there, it's the sort of thing that you'll pick up with greater ease as you continue to learn.
the more a language threads itself into your memory, the more familiar its grammatical 'sound' becomes, whether or not you realise it. sort of how in english there are many rules that native speakers are unaware of, yet they abide by them simply because they know their language inside & out; it just makes sense. I'd say it's the same with other languages.
I'd suggest focusing on each word & its articles. don't worry too much about the expanse of vocab you've yet to learn. duo will introduce new words at a pace that will suit you. if you're having trouble still--write them out in a table to reference as you practice. take your time with each sentence, breaking down the WHY of each word & its article; the same goes with conjugations.
as I said--constant exposure & patience. your brain will absorb grammatical patterns subconsciously--though only if you continue to work at it, even through the frustration. if you ARE getting frustrated, slow it all down & take it one sentence at a time.
best of luck!