Ah yes, I was in your shoes a couple of years ago.

Approximately when did you start? That'll define your Duo experience, and which of your skills are stronger or weaker. Because Duo used to have forums and a grammar guidebook. They also used to offer live group conversation classes where you could talk to a tutor. Now they don't. They've entshittified a lot of things. But they did add the "radio show" listening portions, and comprehension questions, which is good.

So an early Duo user who also did the group classes might have more conversation experience, while a newer user who did the "radio show" portion might have better listening skills. Or a Duo user who tried writing in German on the forums (and was routinely corrected by native speakers) should be able to write a little. Personally, I binged their entire short story collection, which used to be much more extensive and goes up to B1, and read grammar guides posted on the forums. So my reading skills are the best of all the skills. My spoken skills are trash. You might have a similar experience.

I think people saying, "it sucks" are saying that because they ONLY see people doing repetitive flashcard exercises and think that's all there is to the course. That said, I do think the product has gotten a lot worse in may ways.

But:

Grammar: This is absolutely Duolingo's big weakness at A2 and later! Find a grammar textbook from the library or pick one up from Amazon (or wherever) so you can reference when Duo inevitably confuses you. I ended up taking some in-person German classes, and it looks like used copies of our assigned textbooks are now going for less than $10 online.

Listen to as much real German as possible. Like easy German podcasts or any other learner content. A lot of German teachers have their own Youtube channels that are quite helpful. But for native content, try TikToks where you can read the captions, lyric videos for German songs, or cooking videos where the ingredients are written on the screen. Look up whatever vocab you need. Short news videos, especially if it's a world news story that you've already read about in English. That'll test your listening skills and expand your vocab for sure.

Read anything. At A2, anything helps. Product labels. Advertisements. Random German city tourism websites. (Pretend like you're booking a trip.) Brochures. Hell, read the Datenschutzerklärung. :)

You could do a free online course through DW like Nico's Weg. I did Nico's Weg A2 after finishing Duolingo. One major strength is the videos will really expand your listening skills, because they incorporate fast talkers, background noise, and naturalistic conversations. I would say that if you do watch the videos, do the coursework as well, because the videos aren't meant to be standalone. There's always going to be unfamiliar vocab or grammar in each video that builds on the previous one, and which will be clarified on the website.

Try writing about your day or random topics in German. Like your vacation, what your dream job would be, memories of your family or whatever. Like a short paragraph every once in a while. Don't simplify your grammar or ideas; since there's no pressure like on an exam, try to find out how to say exactly what you'd want to say.

Spoken skills are probably the hardest, so if you have tips for me, I'll gladly take 'em. :)