Not sure what your practice is like with the app. But for a stability practice which is the more common type, I would set a timer and sit with good posture so your skeleton is supporting itself. Focus on your breathing especially within the body. It's important not to meditate from the head but from the body. When your attention wanders and you notice it go back to concentrating on your breathing.

Basically listening what to do - mostly it is focusing on breath. Let go of thoughts. Bodyscan. Well this.

I am not sure why I don't just do it on my own but somehow I dont without a primer

It sounds to me like you will reach a better practice without the app regardless of cost. I would force myself to do it without the app for 20 or 25 minutes, just wait for the timer to go off. Do that a few times and it will get easier. From my experience you will get better results this way as the guides are ultimately a distraction.

You can actually repeat the Basics course infinitely - 10 free sessions. I do one per day, it’s always fresh thanks also in part to the varying “clouds in the sky”.