Before you actually start listening you should speculate about the topic. If possible you speak loud: „I think the podcast could be about / deals with the question / presents arguments for and against …“
While listening you should stop the recording from time to time and repeat in your own words what was said.
At the end of the podcast you should summarize in your own words the main points / arguments / aspects. Again, if possible, speak loud. Of course it’s much better to actually tell somebody else (parents, friend, etc.) about the podcast.
After a few days you should „revise“, i.e. check how much you remember from the contents (Inhalt) and the vocab. Probably you’ve already forgotten most of it, so listen to it again.
A good place to practise those tips is BBC 6 Minute English.