Then you should start with that. I wouldn't advise anyone to try and tackle QFT without a good grasp of QM at the level of, say, the textbook by Sakurai.bachir1994 said:very uncomfortable in quantum mechanics.
Quantum field theory is a branch of physics that combines the principles of quantum mechanics and special relativity to describe the behavior of subatomic particles and their interactions.
Quantum field theory is important because it provides a framework for understanding the fundamental laws of nature at the smallest scales. It has been successful in predicting and explaining many phenomena in particle physics and is essential for the development of technologies such as quantum computing.
To start learning quantum field theory, it is important to have a strong foundation in mathematics and physics, particularly in calculus, linear algebra, and quantum mechanics. It is also helpful to have a good understanding of special relativity. There are many textbooks and online resources available for beginners to learn the basics of quantum field theory.
The key concepts in quantum field theory include fields, particles, and interactions. Fields are described by mathematical functions that exist throughout space and time, and particles are excitations of these fields. Interactions between particles are described by mathematical equations known as Feynman diagrams.
Quantum field theory has numerous applications in physics, including particle physics, condensed matter physics, and cosmology. It is also used in the development of technologies such as quantum computing and quantum communication. Additionally, concepts from quantum field theory have been applied to other fields, such as economics and information theory.