Hello! If your goal is to be able to understand Korean content without subtitles, then I think self-studying grammar and vocabulary is a good idea. I know you said you already have some knowledge of Korean, so I would refer to my masterlist and start from wherever you feel appropriate. I also recommend diversifying your study material and looking at other resources on Tumblr, YouTube, and on the Internet elsewhere. There’s a lot out there!
As for your second question, I think it makes more sense to study vocab and grammar at the same time. As I’ve said before in previous asks, I was never that disciplined with my studying, so I can’t really give you concrete study techniques. I think I got where I am today by regular exposure (on top of taking Korean courses and studying abroad lol). But if you don’t have those opportunities, using whatever resources on the Internet can get you far. As you get comfortable with both grammar and vocab, I recommend exposing yourself to content like webtoons in Korean and K-dramas. These will help you with your reading and listening comprehension. There are plenty of webtoons at varying levels of difficulty, and K-drama actors have clear diction that is easy to understand. Again, I don’t exactly have concrete techniques for how to eventually ween yourself off of subtitles/translations (since I myself still use them), but in my experience, exposure alone is enough to at least allow me to read webtoons and watch K-dramas without relying super heavily on the translations. Consuming this content will also teach you how natural Korean is spoken by natives. I hope that makes sense!
If you’re concerned about speaking, the best way to get better is to converse with others. You might not know other people who speak Korean, but you can still practice with others for free on Hilokal, where I used to teach live lessons. It’s a nice, low-pressure environment that can help you get more comfortable with speaking and learn alongside other people just like you!
Also, I generally don’t recommend using translators to help you learn a language, especially if you’re an English speaker learning Korean. It’s more useful for you to understand the meaning of the Korean itself than it is for you to get the perfect translation. Korean is especially difficult to translate into English (in my opinion), so a translator might not give you a clean, accurate, and natural translation. Unfortunately, I can’t think of other ways to fact-check your sentences otherwise lol. But I think that looking at enough sample sentences will help you become better at constructing your own. And something that helped me feel more comfortable writing and speaking when I was abroad is that, even if I make minor mistakes, chances are that other people can still understand me. Maybe keeping that in mind can make the learning process a little less stressful 🙂
Maybe this advice isn’t new for you, but I hope it was still helpful! Thanks for the question and good luck! 화이팅!
Good advice for general language learning as well.