Hi.. It will better for us to understand more clearly if you mention where you have save your all remaining docs such as in android phone, in windows, in mac etc. Here i briefly explain all scanning process and how to save scanned document. Hope this will help. In case you face any issue then you can refer to manual mentioned in last of this post for your help.
* Connect your scanner to your computer via USB or network.
* Install the scanner drivers if Windows doesn't automatically recognize your scanner.
* Place the document into the scanner glass.
* Set your scanner's format to PDF.
* Press the "Scan" or "Start" button on the scanner.
* Use a scanning program if you can't start scanning from the scanner.
For more help visit Canon MG3620 Manual- https://guideusermanual.com/product-name-pixma-mg3620-manual&po=331778&lang=English