Maybe you can begin with an application related to something you like or you need. I know I’ve learnt Objective-C / Cocoa programming by making myself an account management software, because I needed one.

If you begin with a project you don’t like, that’ll be the best way for you to be bored by C++ ! ;-)

Have you done ‘Hello world” yet?

I never thought of this. I have a couple of years of coding in c++ making muck up console applications. So, I am also interested in the answers of your question now.
One thing is making a small application and go from that.
To answer your question, maybe you’ve thought of a program that would come in handy for you, but you’ve never seen anything like that around. think what would be a handy program to have and make it your project.

If you expert in C++ make a game Ticktactoe.