Hi Christine
Well, about sorting alphabetically, it should be done automatically when click the column Name.
There's also an option for you to keep folders above files in menu Finder > Preferences > Advanced.
Also check menu View > Show View Option and see if anything there might help you get the exact view of the files as you like.
About the blank spaces, that's a strange problem.
Let's first try some things to see if it gets any better
Reset SMC https://support.apple.com/en-us/HT201295
Reset NVRAM https://support.apple.com/en-us/HT204063
Reboot your Mac holding Shift key to load Safe Mode. it's a longer boot because macOS does some maintenance under the hood and can solve some problems while doing it. I think that can help on that strange behavior in Finder when you delete files.
Check if you have those issues in Safe Mode.
Once done, reboot normally to see if it helped.
Also try creating a new admin user and check if that kind of behavior happens when logged in there. If not, you can move all your stuff over that user and delete the old one.
Last resort would be reinstall macOS.
You can do that 2 ways
First, make sure to backup your personal data to and external drive then create a bootable installer https://support.apple.com/en-us/HT201372
And
1 - Simply reinstall macOS. It is design to save your data, so everything should remain as it is by now, but macOS files will be replaced with new ones.
2 - Make a clean install by erasing the disk before reinstalling macOS. This will get you a factory reset, then allow macOS to update everything, install your favorite apps and copy back your data from the external drive.
(Option 2 is always the best way to get you the top performance of your Mac. If you'd like to do it and need more help on it, let me know here)
