This is available for all proficiencies. It's just much harder to talk for hours in a new language as a beginner. It's usable but requires more effort.
Another thing is that the trial period seems incongruent. To me the structured curriculum is what I really want to _try_. I want to see what the planned lessons are like, how guided they are, etc. But the trial runs out and tries to make me pay right after the unstructured more all-over-the-place feeling introductory conversation, and I'm not prepared to pay at that point since I feel like I haven't gotten to evaluate the main part of the product at all. I would suggest leaving the trial unlocked to maybe the first three structured lessons of the learning plan. Let the user really experience what they'll be paying for.