People are turning to audio and visuals when it comes to technical subjects. However, you should consider doing an ebook first and turning it into an audiobook through a resource like Audible's ACX platform. You can hire a producer either through a royalty share program, so you don't have to shell out upfront cash, or you can do a pay-per-hour hire as well.
Considering that you have a finite amount of time, passive income should make up a large part of your work. If you're serious about generating any semblance of income online, then passive income should be one of your sole goals and ambitions. Why? Wouldn't you prefer to do the work one time and get paid repeatedly as opposed to relying on your time to generate that income? Invest the time at the front-end so that you can reap the benefits on the back-end. This means putting in a bit of sweat equity and not getting paid today. Rather, you'll get paid somewhere down the road. And you'll continue getting paid whether you keep building that passive income stream or you stop.
Then once you’ve got your domain name and hosting sorted out, it’s time to pick a CMS, or Content Management System, that will let you update pages, build your blog and integrate with all the other services you need. It’s hard to go wrong with WordPress—the CMS powering close to a quarter of the internet. Keep in mind that eventually as you start growing traffic to your blog, you'll be wise to invest in a managed WordPress hosting plan from a company with great service like Kinsta, where all of the settings are custom-tailored and optimized to work particularly well with WordPress-powered websites.