Many academic institutions have a 'supercomputer' center. There are also organizations (e.g., Metacentrum in the Czech Republic) that allow access by affiliated institutions to shared computational resources (with ready-to-use software, including various molecular dynamics simulation packages), but to get an access, you must be a member of an affiliated institution or have a collaboration with a member.
One could use CHARMM GUI to generate the system and topology. Then MD simulation can be performed on a local machine or on super-computing facilities whichever the person can afford.