Under the Help menu, you'll find a PDF document called "02 AC 12 Getting Started.pdf". A similar file is in the 11 help menu / file structure.
See pages 23 through 48 for migrating projects from 9 upwards.
To migrate earlier projects, you have to first convert them to 9 or above:
http://www.archicadwiki.com/TechNotes/Conversion%20of%20old%20ArchiCAD%20project%20files%20into%20Ar...
If you don't have a CD with 9 on it, you'll have to contact your reseller for a download site or a means of getting a CD. If you are on an Intel Mac, I believe you will definitely need a download, unless you have a PPC Mac laying around. (With CD only, I believe you have to install on a PPC Mac and then copy the AC 9 application folder over to the Intel Mac since the installer will not run properly on the Intel Mac.)
Of course, if your old files were not saved in PLA form, then you probably also need the library used when it was created...
And, as Dwight said, if you are using the Educational version, you have lots more problems... It is not intended for real projects, nor student projects that span more than a version or two...
Karl
One of the forum moderators
AC 28 USA and earlier • macOS Sequoia 15.2, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB