Tweak a form in wordpress so as to accept file upload

I am wanting to tweak a form in wordpress.
Details of how to create as follows: https://kinsta.com/blog/contact-form-7/

I have ALMOST completed it, but I need:
- accept/upload file of any type with max 10Mb
- save file to disk on host site
- reduce comment field box size
- send an email to me upon successfull form fill
- feed back to user "Message recieved"

See work completed thus far:
https://www.socialcommentry.com/please-upload-report-below/

Note: No access to website will be given, you will be required to direct me to make changes live via video call.
Note: Job will not start until 10.30am, Monday 12th Jan. 2026 Perth time.
See: https://time.is/Perth