If you want to get into web development specifically, c++ wouldn't hurt but wouldn't be the optimal path to take. I'd start with Javascript, and work entirely on localhost. Make an index.html page that references a script.js page and point your browser at it. Make a calculator, or a demo shopping cart, or a running log. Get very comfortable with event handling, updating the html from javascript, setTimeout/setInterval, and try to incorporate some AJAX calls to an external API to practice getting data from a server and updating the HTML. There are plenty of stock apis or whatever available for free if you google.
Then, you're going to want to learn a server-side language, something like Java, C#, Python, Ruby. Avoid PHP like the plague. I use C# and love it so that's what I'd recommend, but it's down to preference. Using whatever you decide on, set up a full website with a server, database, and HTML/JavaScript (still doing this locally, all on your computer). Get to where you can build a form in HTML, submit it to your server with javascript, and save the information in the database. Give some thought to how you'd add authentication to it.
If you can do all of that, and you're keeping these demo projects in source control and hosting them in Github, you'd be ready to start applying to entry-level jobs. Bonus points: learn linux, learn React or Angular, learn a CSS framework like Bootstrap or Bulma.