You have multiple problems here. The unavailable iPhone means its contents are gone, the unavailable email means reset mail is unavailable, and a forgotten password for the Apple Account and that apparently without a good reset path. This is not an auspicious position for gaining access.
You can try Apple Support and see if they have a path through all of this to regain account access, but this Apple Account may be gone.
Even if you regain access here, I’d seriously consider a feature phone here, too. I tried to keep a couple of folks going on their own Apple gear, but came to realize that experience and that effort was frustrating them, and the whole preservation approach was a mistake. A feature phone or a cordless for essential communications avoids the difficulties inherent in modernity. At some point, I’d also lock out calls and texts from unknown numbers, too. This having answered some of their incessant scam calls.