Mac users without any access to Windows have to export as 3DS (e.g.) from SketchUp and use the 3DS Import add-on (download from the AC Help menu) to import that file. Only SketchUp Pro can export as 3DS though.
There may be some skp-to-3ds converters out there somewhere via Google otherwise?
(Some people use a Windows virtual machine on their Mac to run AC only when they need to use the add-ons not available for Mac ... and then continue their work on the Mac side.)
One of the forum moderators
AC 28 USA and earlier • macOS Sonoma 14.7.1, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB