What courses would benefit me the most
You can’t really target your education to a specific job - that job may not be there when you get “ready”. This is probably going to take a year or two, realistically. #ymmv
I think the best thing to do is to learn. You want to build a solid tech stack. For that you need a frontend and a backend. I think frontend is easier to get a job in starting out (not that it is ever “easy”).
For frontend, you at least need to learn HTML, CSS, and JS. The first 2 FCC certs do that, but you can learn them somewhere else. Next, I think you need a modern interface library/framework. FCC teaches React, but Angular is another viable candidate, and some would argue that Vue is. Of course there are also templating languages that can achieve some of those. But the first 4 FCC certs will give you a solid frontend with React and a little jQ knowledge, and a few other libraries.
Of course, you’ve mentioned Go. You can certainly write a backend in Go. I think it is much less common than Node (or Java/Ruby/Python), but it is certainly doable and some companies may want that specifically. As you may have seen, there are some rather ardent Go supporters, but that can be said of any language. Be careful about people saying, “This is the new tech that will take over…”. 99% of the time, history proves them wrong.
But as I said, I think it is a lot harder to get a backend job as your first job, so they may not care that much what it is. But it shows that you understand servers and also allows you to make much better demo projects.
After you have a decent stack, the important thing is going to be to keep learning and to keep building increasingly complex projects to show off your skills. That would be a good opportunity to learn things like Shopify, etc. That is again looking at a specific job, but that is a common enough thing that it still could be a good thing to learn. That combined with a good resume and portfolio, and some honed interview skills will almost certainly eventually lead to a job.