Linux

a more obscure option is exiftool – and documention

• setup an input folder and a destination folder beforehand
• copy photos from phone to input folder
• bonus: decide on separate suffix or initials for each of you

exiftool -progress -d <destination-folder>/%Y%m%d-%H%M%S-<suffix>.%%le "-filename<CreateDate" <input-folder>

    -progress
        verbose and shows an [x/y] progress
    -d <destination-folder>/%Y%m%d-%H%M%S-<suffix>.%%le
        renames to YYYYmmdd-HHMMSS-sfx.ext format
        and lowercases the extension
    "-filename<CreateDate"
        uses the image creation date (from EXIF metadata) for the above naming scheme

there's a utility named rename that will rename based on regular expressions. I think all the things you listed can be done by making a suitable regexp for each case

I'm sure there is a great bash option but my bash is rubbish.

A quick python script would work.

From the datetime module you could use fromisoformat() method to get the date then use the strftime() to get your Year-month-day format. All this after reading the directories contents with the os.listdir() or os.walk() loops. You could parse the filenames for IMG/VID using if "VID" in file_name logic. You could strip the date from the file_name before using datetime with string slicing. Lastly you can use the os.rename() method to rename the file.

These steps are a bit out of order. But the ingredients are there. With a bit of search engine magic you should be able to work up a script. I would set up a testing folder and test it well before using your script on things you don't have a back up of.

When I started learning scripting, some internet guy recomended me this resource: https://mywiki.wooledge.org/ I really like it, espescially FAQ. I guess you would like Parameter Expansion chapter.

Take a look into regular expressions - sed or awk. What you wrote would go something like this

#!/usr/bin/env bash  
for F in *; do  
  NEWNAME="`echo $F|sed 's/\(....\)\(..\)\(\).*\.\(...\)$/\1-\2-\3.\4/'`"  
  if [ -f "$DESTINATION"/$"NEWNAME" ]; then  
    NEWNAME="${NEWNAME}_1"  
  fi  
  #mv "$F" "$DESTINATION/$NEWNAME"  
  #let's debug instead  
  echo "$NEWNAME"  
done  

https://stackoverflow.com/questions/638975/how-do-i-tell-if-a-file-does-not-exist-in-bash#638980

man mv

https://tldp.org/LDP/abs/html/string-manipulation.html

https://www.digitalocean.com/community/tutorials/linux-sed-command