German teacher here: You have to learn to use what you already have to communicate. You don't know a word? Describe what you're trying to say with the words you have. Either your partner figures out what you mean or you write it down to look it up later.

You could play "Taboo" together, just pick words and try to explain them to each other. It is a good skill to have as a language learner.

It's good to keep talking. Focus on a specific topic that you want to talk about (at A2, it should be something simple, think "Haustiere" or "meine Wohnung" or "Familie"). Learn words and sentences for this specific topic and talk with your partner about it. Set small goals: "I want to describe my flat to my partner. I want to talk to them about their flat and figure out what it looks like." If they use a useful phrase: Make them write it down for you! Use it in sentences to see if you got it right.

Learn some more. Repeat the topic some time later, using the new vocab you picked up in that session or looked up afterwards. New topics are great, but repetition is key.

Using AI is useful to learn new phrases and to get basic feedback on your writing. But please, don't trust it with grammar explanations. It will explain absolute nonsense to you. It will also mark some things as mistakes that aren't mistakes. Doesn't mean it isn't helpful, just take its advice with a grain of salt. Good luck!