"I eat lunch."
I see you are achieving a lot here. When you finish the entire course for a language here, where do you go next on the internet to solidify further? I feel like I would first have to do a bunch of exercises memorizing vocabulary from all the kanji and advanced characters much the way elementary students in Japan would have to do for this first language I am tackling. What is the next general step in language learning for all languages given one has completed a Duolingo course?
I am using Human Japanese app in conjunction with Duolingo. It teaches a lot of the same lessons, but in a much more in depth way.
In addition, I recommend the Hello Talk app. You can speak with native Japanese speakers who are looking to learn English, giving you some real practice in using the language.
Remembering the Kanji by Heisig is a good way to learn all the official kanji. RTK 2 teaches you readings and 3 teaches you more kanji. I'm going through RTK 1 right now and it is really satisfying to know what kanji mean. Im not sure of the best way to learn the pronunciation of all the kanji but i think listening with subtitles will be what i try first. Btw anki is a blessing just dowload the right deck.
the prefix is beautification thing, there is more about this here:
It varies from word to word too, but in this case, the word 昼ご飯 is already a politer word than a counter-part like 昼食【ちゅう・しょく】and in that case using お～ sounds better. However, it can be skipped but it doesn't really affect the deferential level of the sentence but the way the sentence sounds.