So when I take a screenshot and the image dosnt pop up in the bottom left corner. It freezes and I couldn't unlock the phone and I always get trapped in my home screen.
You can try powering off your phone and holding the side key and volume up key. Then you may select wipe cache/partition. This will resolve some issues and will NOT wipe your data.
Clearing the phone's cache partition should help with lag, as will periodically restarting your phone. You can set your phone to automatically restart on a schedule so you don't have to remember to do it. Go to the device care settings and select auto optimization and then select what day and time you want your phone to restart. You should have it restart at least once a week - it cleans out temporary junk hanging around in memory. There may be a slight delay in the screen shot appearing on your screen, so waiting a few seconds before attempting to do anything else may prevent the lag.
