Teach Javascript. It drives all web pages, is the right place to learn (the tools to deal with) asynchronicity, can be the foundation for crazy functional stuf

Teach Javascript. It drives all web pages, is the right place to learn (the tools to deal with) asynchronicity, can be the foundation for crazy functional stuff (cf https://www.gitbook.com/book/drboolean/mostly-adequate-guide/details https://www.gitbook.com/book/drboolean/mostly-adequate-guide...), can be strongly-typed (aka TYpeScript), has a very decent editor (VSCode). My humble 2 cents.