How to allow users to upload files in the form?

--one form will let the user upload 1 image and one form will let the user upload up to 5 images

You can indeed allow your users to upload files in your forms, you can set the file upload field to accept one file only or it can also accept multiple files in the same field. 

Also, you can set a max number of files that can be uploaded in the field: 

Here are also some guides that will help you with the file upload field: 

How-to-Create-Upload-Forms

How-to-Change-the-Allowed-File-Types-Extensions-in-the-Upload-Field

Changing-the-upload-size-limit

If you have any question, please let us know.