can an employer make an employee that has informed them of school after work still make them park at an offsite facility

I'm assuming that this is a private employer, not part of job assigned by the school as part of a work study program.  In such a case, your employer would, unless it was provided for in your employment contract, have no responsibility to make sure that you make your classes.  If complying with the terms of employment set by your employer compromises your ability to get to class on time, you may have to get a different job.