Hello, sorry you are having installation issues. 500 Internal Server errors could be caused by a plugin or theme function conflict. Are other plugins installing successfully? If not, there may be an issue with the WordPress install.
Can you try deactivating plugins and retrying the install? If you that does not resolve the issue or track down the conflict, can you let us know what theme and plugins you are using? From there, we can help try to recreate the error environment.