Okay kiddo, let me try to explain this to you in a way that you can understand. Islam is a religion, which means it's a way that people believe in and worship God. Muslims are people who follow Islam.
Now, some people might form a political party and call it an Islamic Party. This means that they want to run the government based on the teachings of Islam.
However, some people don't think that mixing politics and religion is a good idea. They believe that everyone should have the freedom to practice their own religion, but the government should be neutral and not favor one religion over the other. So, while they might agree with the teachings of Islam, they don't support an Islamic political party.
In short, it's okay to follow your religion and beliefs, but when it comes to running the government, it's important to keep things fair and equal for everyone.