Changing supervisor before starting the PhD - not selected I approached a supervisor about a PhD application. At this university, you must have two supervisors, so after a meeting, he invited the other "supervisor" to discuss the topic.
Honestly, this new supervisor doesn't suit my topic. In fact, he proposed some topic changes that I am not happy to do. However, for the rush of the moment and the nervous, I said yes. After, I checked the credentials of the new supervisor. He just graduated last year and I would be his first PhD student.
I received the offer letter and this last supervisor was appointed as the main supervisor.  I received a scholarship from my government (not from the university), so no funding is attached to the supervisors or topic. I haven't "officially" started the PhD.

I will have a meeting soon and I was wondering how I could ask to change the main supervisor? I will argue that I want to focus on my original topic, but what to do if they say that I can change the topic, but with the same team?  Is it wrong that I would like to have a more "experienced" supervisor as the primary supervisor?

Thank you.
Your wishes and concerns are valid, but your options are limited. You say you agreed, which was not your best choice. Of course you realize this, but maybe too late. 

Unfortunately this is more of a personal relationship issue than one for rules. I know how bad it can be to have an inexperienced, ill-matched, advisor, especially if you aren't enthusiastic about the topic. 

One option is to go elsewhere for your degree - an extreme solution that will cost you time and perhaps, money. 

A possible solution, depending on personalities is to go back to the first professor, with whom you seem more comfortable, and lay out the situation, in essence begging to work under his/her direction instead. Don't open with the suggestion that you may need to withdraw if your request can't be granted and think about whether that is actually what you would want to do. But your possible withdrawal might be a last resort argument. It is a bit dangerous to use, however, if made in such a way that anyone, especially this professor, thinks less of you as a result. 

One outcome of such a meeting might actually be that the professor can convince you of the correctness of the current situation (with the new advisor and problem), based on his/her reading of the state of the art. It is useful if you have a senior professor keeping a bit of a watch over you and a junior professor as the process unfolds, so maintaining a good working relationship is essential if you intend to continue.