Code a program which interact with a website

I'm trying to code a program which can interract with a WebSite. The main things I would like to do is to fill some information, find items, and click buttons on a determined URL. And I would like this to be done in the fastest way as possible.

I've just finished a project for University with C++ and QT, but I never interract with a website so I'm sorry if I'm not gonna provide some code. I've found some libraries like Curl or like QTWebKit (is it still aviable?). Is QT a good platform for this? Is c++ the fastest language to do this? Which Library/stuff I need to do this? Do you have any advice on where to start it?

I'm sorry if this could be off topic, but I would like a sort of incipit on where to start and which language to use!

Thanks!!