I want to get a large collection of quantum circuits that matter to practitioners in quantum computing. I want a get many complete quantum circuits. For example, 1 million QASM files. However, I could not readily find a large dataset. Are there any places I could find it?
I would recommend this paper: https://arxiv.org/abs/1804.03719. You can find there information on algorithms and how to deal with noise and errors in quantum circuits. Moreover, it can help you to "generate bunch of QASM files" implementing algorithms presented there.