lasta

In some cases a title or relation to you could work, like doctor, professor, whatever department they are in, dear reader/patient/customer.

Or you could omit gendered references altogether and use a general greetings (hello/greetings, good morning/afternoon/evening).

For a while I was tracking my expenses in a LibreOffice Calc sheet since they are not complex, but I heard positive things about these two from other users:

https://github.com/actualbudget/actual

https://github.com/firefly-iii/firefly-iii