How to get the most out of a language tandem?

I’ve just been given a tandem partner by my university and am a little nervous about getting started!

For some context I’m B1 level, have had a mix of self study and classes for the last year and a half and am now living in Germany.

I have had a tandem partner that I have met in person every 2 weeks for about 6 months but I really don’t feel like I got much out of it. Unfortunately I just used to dread our meetings and I wouldn’t really prepare topics to talk about. We just usually just talk about what we’ve been getting up to but I feel quite comfortable with this kind of conversation so it was never really challenge.

I’ve got slightly higher hopes for this tandem as she is my age (my last one was quite a bit older). And hopefully she’s nice and we can actually become friends??

We’ll meet in person every 2 weeks. Do you have any advice to make this tandem more successful than the last?

I imagine people are going to suggest selecting a topic before hand. But how do I pick a topic 😰 and will it not make the conversation a bit awkward? And also I’m not even sure I can talk about one topic for 30 mins or more!! My speaking is quite weak…