WordPress is my choice, and it is probably the most popular blogging software in the world.
That said, it isn't blazing fast (although you can get it really fast) and tends to have some security holes.
Easy workarounds: cache the hell out of it, daily incremental backups, update all plugins and framework updates, keep a secure server in general, reduce footprints (wp-admin, rename db prefixes, etc) and simple stuff like not using bloated themes and plugins.
I love WordPress, I've been using it for 11 years now on my main money making website and as per my website speed checker it is faster than 90% of the websites out there.
I've only been hacked once, and that was when that huge XML-RPC attack came out, and that basically got everyone. I was "down" (I took myself down) for about 1 hour, and didn't lose any data.
This fits your exact needs: custom domain, free, can handle a lot of traffic, and is pleasurable to use.
If you want to learn programming sure, write a CMS. If you want to start a blog, install WordPress.