Level 2
You wont be able to serve them on the same port if you want webpack-dev-server or similar. They will have to have different ports. You could build your assets into a production bundle if you're not working on them for a while then server the site on the single port, perhaps?
Alternatively there are cli tools that manage running process simultaneously. Packages like concurrently which is an npm module, off the top of my head.
Assuming youre running php artisan serve and npm run dev or something? Not sure if concurrently handles php process as well as node processes. But I'm sure there will be something out there that runs commands concurrently like this