Hello @ekstrandr , and welcome to the Community. I do not believe you can open a module for just 1 student. However, if you put requirements that 1 module has to be completed before the next module is opened, then when your student finishes the first module, the 2nd should open for them.
Another way to accomplish this:
There is no direct way to open modules for one student when they are locked.
You could unlock the module for all students. The content would be available to everyone, but you could open the assignment/discussion/quiz for the one student before it is opened for all the other students.
Click add at the bottom of the assignment/discussion/quiz edit page. Add the one student while leaving the Everyone Else there. Then setup the one student to take the assignment/discussion/quiz earlier than Everyone Else.