adb - How to pull data from internal memory on an unrooted phone?

Yesterday, I suddenly discovered that I had lost all the user files on the internal memory of my android phone. All my photos, my music, my PDFs, audio recordings, everything. I will explain the events leading up to this in a separate paragraph below.

I have a Lava Z90 phone and I do not use an external SD card, so I must work with my phone to recover all data. I've been googling and following stuff I get from the internet(including Stack Overflow). Here's what I have done so far.

1. 
   

   Tried using photo recovery apps available on Play Store. None of them worked.

   
   


2. 
   

   Decided to go more technical. Enabled USB Debugging and OEM Unlocking from Developer options in my phone. Then I used ADB pull command, pull /dev/block/mmcblk0 /home/data.img to try create an image of the entire internal storage so I can analyse it using PhotoRec. It says pull: not found

   
   


3. 
   

   I assumed this is because my phone isn't rooted? I tried to root it with the KingoRoot apk but that didn't work. I have Ubuntu on my PC and there is not KingoRoot for Ubuntu. My next step would be to use Wine to run KingoRoot on my machine and try to root my phone that way.

   
   

I have the following questions:

• 
  

  How can I create an image, a data dump of my entire internal storage that i can later analyse for my data?

  
  


• 
  

  Can I do it with an unrooted phone? If not, how can I root my phone with ADB?

  
  


• 
  
  

  Am I going about this right? Is there a better, easier way to recover data that I should use instead?

  
  

Thank you very much.

How I lost my data

I recently uninstalled the TikTok app from my phone. Yesterday I connected my phone to my PC over mtp and found that there were certain leftover folders on the internal memory. One was a folder with Chinese name, one was a folder called ByteDance and one folder called Thumbnails. I assumed that the first two were leftovers from the TikTok app and the third was mere thumbnails. So I deleted them to save space. Nothing happened that day, except that I couldn't access any of my WhatsApp images through WhatsApp(they were still accessible through the gallery). However, when I woke up the next morning, all my data on the internal memory was gone. I still have contacts my messages and my settings, just that everything that was accessible through the file explorer has disappeared.