After you remove or transfer your SIM card, insert the tray completely and in the same orientation that you removed it (it will fit only one way). Use only the SIM tray that came with your device. For example, a SIM tray from an iPhone 6s will not fit in an iPhone 7.
Total test time is 205 minutes if taking the Writing/essay. Without the essay, the ACT is 155 minutes actual test time. Individual sections are always in the order of: English (45 mins.); Math (60 mins.); Reading (35 mins.); Science (35 mins.); and, optional Essay (30 mins.).
Four to eight hours. Take one practice test and review the questions you missed. Go to the MPRE review class if your school offers one (should be 3-4 hours) and pay attention. Failing that, skimming the BAR/BRI materials for a comparable amount of time should work too. The MPRE is easy.