You have already flashed your SD memory card with our system image.
check out this article If you haven't done it yet.
Now just follow these steps
Start the raspberry pi and connect a USB keyboard and mouse to it.
Minimize the Mawaqit window with the F11 key on your keyboard
Connect it to the internet (Wi-Fi or Ethernet cable), you can use your smartphone shared internet. This is needed only for the synchronization step and will not be needed after.
Synchronize the Mawaqit app with your account, let yourself be guided on the Mawaqit window
After validating the synchronization form you will see your Mawaqit prayer times display. Finally press F11 key to maximize the Mawaqit window.
Important : The Raspberry pi doesn't have an RTC clock (an electronic component with a battery) which allows keeping the time correctly set when it is off.
So it is advisable to equip the raspberry with RTC if you do not plane to connect it to the internet, this will avoid loss of system time in the event of a power failure. Just plug it in as illustrated below.