"My phone is so old I can't update the software in any way."

Jack - if this is so, you seriously need to consider getting a new phone,
because by now your old one is probably very open to hacking and ID theft.

I wouldn't risk any personal ID info, email accounts, phone umbers, contact lists, etc,
on a phone or tablet that no longer provides software updates...

For instance, my old Android devices still work well enough for some basic apps,
but I use an expendable spare Google ID that doesn't link to any of my real ones...

My old Windows 8 phone [anyone remember them ..]
is now just used as an alarm clock,
and to check emails on an old false ID account,
that aquaintances from up to 20 years ago might still very rarely try to contact me on...