There’s a variety of free accounting programs available.
Let’s start with three great options.
GnuCash
If you want to learn the art of double-entry accounting, but don’t feel like spending a bunch money on bookkeeping software, look no further than GnuCash.
GnuCash is open-source software, developed and maintained by people who provide their talent towards the better good.
It’s 100% free, and runs on Windows, Mac, Linux, and more.
I use GnuCash as my daily driver, both for personal finances, and for business.
Everything you need is built in.
There’s no bells or whistles, but if you learn this program, you will understand the fundamentals of double-entry bookkeeping.
Firefly III
This one’s a self-hosted double entry software that runs in a web browser.
You will have to run a web server to use it.
Actual Budget
Here’s another self-hosted web software, but it’s single entry bookkeeping.