There isn’t a clear cut path to follow, per say.
It depends on what you want to learn, and achieve.
Re-building your husband’s website is a great start. And, yes, using WordPress is one way to go about this. Knowledge of this particular platform is in high demand, though a bit saturated, and it’d definitely be a great way of expanding your skillset.
If you go this route, simply try figuring out how to make a WordPress theme from scratch. You’ll learn a great deal that way. And it’ll look nice on your resume should you wish to use it to demonstrate your skills to employers.
Once you’ve grasped the core concepts of JS, you can then move on to use a framework, such as Vue.js, React.js, or even just the jQuery library for simpler tweaks.
You might want to do the same for CSS, which has frameworks such as Bulma.io, or Twitter’s Bootstrap. They can help you speed up the development process.
Hope this helps, and feel free to ask should you have any more questions!