Try emptying the Safari cache more often or reset Safari from the menu bar.
Go to Safari / Preferences - Security.
Deselect: Enable Plug ins.
Quit then relaunch Safari. If you don't see the beach ball, then you have a third party Safari add on installed that's preventing pages from loading.
Troubleshooting help here > Safari: Unsupported third-party add-ons may cause Safari to unexpectedly quit or have performance issues
BTW... good idea to have a backup browser installed in case you have problems with Safari.
How much free space on the startup disk? Right or control click the MacintoshHD icon on the Desktop then click Get Info.
See: Capacity & Available. Make sure there's a minimum of 15% free disk space.
Run Disk Utility. The hard disk may need repairing.
Using Disk Utility to verify or repair disks