Option 1: You can keep the user count as 1 and Loop count as 100 in your thread group. This way your script will be executed 100 times, without concurrency of users and one user at a time. you can use CSV file if you want to change the user login credentials and other data at each loop starting i.e. different data for different user.
Option 2: Another solution is (a kind of workaround and it will too provide what you need), add 100 thread groups to your test plan in JMeter. Keep the User and Loop count as 1 in each thread group i.e. copy-paste the same and select the option "Run Test Group consecutively" in your test plan. You will get the desired result.
You can add Tree Listener to see if you are getting sequential requests or not.