Not stupid question. Not everyone is expected to know this.
To wipe partition cache on your S24U or other S24 series:
-turn your phone off
-remove any cases to avoid pressing wrong buttons
-connect your phone to a PC or another Samsung device, phone or tablet. Note only USB C to USB C cable will work.
-press the power button and top side of the volume button
-when the Samsung logo appears release Power Button and keep pressing top of Volume Button
-shortly the Boot Menu of the phone will appear
- read all the options, about the middle of the options you will see Wipe Partition Cache
-use volume up and down buttons to navigate the menu
-use power button to select Wipe Partition Cache and press it to activate Wipe Partition Cache
- wiping Partition Cache takes about a second, watch the bottom left of your phone to check if it's done
-when it's done, your phone will automatically select Reboot Phone System, which is on the top list of the menu
-press the power button to Reboot your phone, this is safe and it will not wipe any data on your phone
-when your phone is switched on remove the data cable and Wipe Partition Cache is done.