Additional Study Information: The purpose of this study is to assess the effects, good or bad, of atezolizumab and tiragolumab given with or without chemotherapy (in this study, chemotherapy will be a combination of either paclitaxel with carboplatin, pemetrexed with carboplatin or cisplatin, or gemcitabine with carboplatin or cisplatin) on patients who are able to have surgery to remove their lung cancer to find out if and/or for how long these study treatments may help prevent the cancer from returning. Atezolizumab is a type of drug called a PD-L1 antagonist and is a form of cancer immunotherapy. It helps your immune system to recognize and fight off cancer cells. Atezolizumab is approved for the treatment of a type of bladder cancer as well as some types of lung cancer, but in this study, atezolizumab is an experimental drug for the treatment of resectable Stage II, IIIA, or select IIIB NSCLC. Tiragolumab is an experimental drug and health authorities have not approved its use in NSCLC.