>>31352146So when you read Genki forget about 'learning' Japanese, just do what Genki wants you to do. It's meant to sort of immerse you and provide a foundation more than be a step-by-step assembly guide to Japanese. Look up Cure Dolly's (RIP) videos for grammar. There are specific grammatical structures for N5, N4, etc. Genki doesn't really tackle this in a very systematic order.
For example, for N5:
https://jlptsensei.com/jlpt-n5-grammar-list/So when you hear the sentence you should know what it means if it's in its most basic form.
Another good source is bunpro where you can spam exercises for N5, N4 grammar etc until you're confident upon seeing a sentence that you know what it means (but it is paid).