Yes, you might fail.
Yes, you might lack talent to compose.
Yes, you might lack the skills.
Yes, you might lack the knowledge.
These fears will never go away. Many people get stuck here. They experience their failures in advance, before they even happen. This is called anxiety.
Some people learn not to fight their fears. Some people learn to befriend them and create their art anyway.
What do you fear more? The idea that you might be seen as a fraud or the idea of not trying?