Hi Anet- welcome to 4WM
First, the reason you can't copy your phone contacts to the SIM card is because phone contacts hold a lot more information than the SIM is capable of. You may be able to copy basic info such as name and one number, and many SIM cards do allow more, but most don't.
An easier way out of your situation is to use a small free program that backs up your Contacts, Calendars, SMS and Emails to a backup file you can store on your phone memory card or transfer to the PC for storage, then transfer back after the hard reset.
It is called
PIMBackup by Dotfred. You can select what to backup or restore.