The project isn't big enough for a discord or anything like that. But if the question is about xpath, you can also try stackoverflow or similar sites. But asking here is fine.
substring-after
I'm using the xpath.js module (https://github.com/yaronn/xpath.js) for the project. It supports all expressions in theory and substring-after(./a/h3/text(), 'Blu-ray') is in theory valid here as far as I can tell. But the xpath.js return gets stuck in L4314, and tbh idk if this is a bug or not. You might try to ask the author of that module.
errors
thanks for the hint, I'll try making that more transparent.
./td[2]/text()
I've tried it with the given html in an xpath playground and it works. So I'm guessing you're getting something from outside the html provided here. For reproducibility it's best to give the whole html page or the url if reachable.
Also is there any way to not have the tags in the text and only get what I circled in red exactly.
yes, but it's tricky. here, it's going to be something like ./td[2]/text()[6] because the expression returns several text nodes, and you have to pick the right one. Also see https://stackoverflow.com/questions/4483972/only-select-text-directly-in-node-not-in-child-nodes
xpath playgrounds and stackoverflow is your friend here.