How can I emphasize my interest towards PhD with no real research experience?
This is a pretty specific question but I'm going to try and answer it broadly.

Generally speaking, applicants with no research experience are not appealing or competitive candidates to professors for graduate school. When professors want to admit a student to work with them, they want someone who is going to be able to hit the ground running somewhat - who knows the basics of how research works, who has some ideas about what interests them, and who knows how to do some basic research tasks. Furthermore, they're looking for students who aren't going to realize halfway through their first year that they hate research and decide to drop out. (Which makes me turn the question back on you: Why do you want to get a PhD, if you have no research experience?)

That said, if you have no research experience and you still want to apply for a PhD program (which I don't recommend), you'll have to demonstrate that you have acquired the knowledge and skills to succeed in a PhD program in another way. Being able to live alone isn't the way - they expect that as a basic part of being an adult.

-Recommendation letters will go a long way. Your professors don't have to be famous or personally known by your graduate program committees. They just need to know you very well, and be able to comment on your ability and potential to do research and succeed in the field.
-If you had to do research-like tasks for any classes - like a final project or capstone - you can discuss that, and what you learned and how you will translate that to research in the program. The research C++ developer position is a good example. You did research; use that experience as a basis for further explanation.
-Motivation is good, but you can't just say that you are motivated - you need to demonstrate it in an academic sense. What academic things have you done to show that you are motivated?

However, you will probably need to apply to an MS program first and get some research experience that way.