If you study, you can take part in a training. The primary level is not difficult, but you can also learn by yourself. As for textbooks, Xinhua Bookstore or other bookstores rarely sell them, but you can go to relevant training institutions and order textbooks instead of attending training. I posted the training outline listed by the training institution, hoping it will be useful to you: The quality engineer training course involves the following contents:

1) Comprehensive knowledge of quality specialty: introduction to quality management, supplier quality control and customer relationship management, quality management system, quality inspection, measurement basis, simulated test questions and analysis;

2) Theory and practice of quality specialty: basic knowledge of probability statistics, basic knowledge of probability statistics/regression analysis, common statistical techniques, sampling inspection, statistical process control, basic knowledge of reliability, quality improvement, simulated test questions and analysis;

"QC, QA, package inspection of machinery, finding and solving problems in machining", the above problems you mentioned are also more specific, so you need to master the quality professional knowledge and technology you have learned skillfully and apply them flexibly in your usual production work.