Regarding internal storage files I'm new, hope I do everything right. Ok, I found a file in my internal storage where the path includes DRAWING/TRACKING/DRAFT . I found out there are 907 files within this main file. I hope i make sense. How did these files get put here &amp; how can I delete them.  When try accessing the files,  I get the error msg that I don't have the correct app to open it.
 I'm on a samsung galaxy J7-perx. 
Thanks
You cannot open those files simply because your phone does not have any app to open such files. For example, if you don't have a word processing app, but try to open a .docx file, you'll be unable to open it. Similar is the case here.

If you cannot open those files,you don't need to look for an app to open them, because I can assure you that you'll not be able to understand what is written in then.

Here is what you can do:

Step 1: Scroll through the files, and see if you can associate the file name to any app already present in your phone.

Step 2: If you cannot do that, then copy the whole main folder as it is, with the subfolder, to the sd card.

Step 3: Delete the main folder.

Step 4: In the next few days, try opening every installed and enabled app and use it as normal. Make sure that you use each and every app at least twice after deleting the folder from device storage.

Step 5: If any app misbehaves, then those files belong to that app, and restore then from the sd card to the device storage.

If no app misbehaves, then those files are residual files of some app which you have uninstalled recently or in the past. You may try using each app for a week or so to make sure they don't misbehave. If everything is alright, you can delete that folder from sd card.