When you download some files from the internet using Firefox, I suggest you to set a directory for all your downloaded files. It will be easier for you to find the files because all downloaded files will be saved in one directory.
If you use Firefox you can follow the steps below:
Step 1. Open Edit > Preferences menu.
Step 2. Click ‘Save files to’ option then click ‘Browse’ button.
Step 3. Select your ‘Download directory’ then click ‘Open’ button.
In this sample, I create ‘new_download’ directory.
Step 4. Click ‘close’ button.
Now, every time you download files from the internet, it will automatically saved into your ‘download directory’.