I would say, have a solid foundation in the basics: HTML, CSS, JavaScript, HTTP/S, SQL, and mastery of one language, be it Java or Python. Because if you know one language inside and out, it makes it much easier to deal with any other one, because you can simply tell to do the equivalent in the other language, and do it the right way.
One of the best things about using Claude Code for me, is I can easily generate the documentation about what my code does, and it will even point out potentially better ways to do it. That’s why I prefer it over CoPilot.
Those aren't "the basics".