Pi.ai is an interesting Ai tool. It is meant to be a sort of companion, a shoulder to lean on, to be safe and approachable and appropriate for all ages and ability. It can help drive a conversation (to an extent) and is a good beginning point for trying Ai, and a reasonable choice for kids. That said I recently started using it to practice French, you can have it speak at different levels, and it will ease up to your comprehension point. It started by including some English explanations, and as we advanced moved to only French and clarified in English only when asked. It is a free tool and is nice companion to other language learning.