No devices connected?

I recently got a new laptop… On this I would like to download a few apps with Google Play (Play Store) … And so I just created a new Google account… Unfortunately it says that no devices are connected… That's why I signed in with my mother's Google account (which she also has on her cell phone), but then the apps I downloaded on the laptop appeared on my mother's cell phone and not on the laptop as desired…

… Has anyone already had an experience with it and knows what to do?

… I would be very happy about a nice and conscientious answer…

Best regards

idrinktea2020

You can't just download such apps on your laptop. And not via the Google Play Store either. You have to go to the Microsoft Store or something and download the apps there. With Instagram, I'm not sure if it exists there, but you can open Insta as a tab on the browser.
So you can only download something with the Google Play Store if you have logged on to the mobile phone with the same account and if you then download something from the PC it will be automatically downloaded to your mobile phone.