Pretty sure it is Safari, when I use Yahoo in Chrome it is fast and no beach balls. How can I update or reinstall Safari? If I click on the Apple icon and updates there is nothing about Safari. Can you help me update? Should I first delete my copy of Safari? How would I do that? Not yet ready to update to Sierra. Also, when I use Safari on my MacBook Air I have no problems.
To update Safari, open the App Store app on your Mac, then click Updates in the toolbar. Click the Update button next to Safari to download it.
However, I suspect that may not solve your problem. I'm beginning to suspect that the problem is that you need to fix/update Flash. Do this:
Uninstall the copy of Flash that you have installed with this uninstaller:
http://helpx.adobe.com/flash-player/kb/uninstall-flash-player-mac-os.html
Download the full installer from this Adobe page:
http://fpdownload.macromedia.com/pub/flashplayer/latest/help/install_flash_player_osx.dmg
Use it to install a fresh copy of Flash Player.
Now make sure that Flash is enabled in Safari.
In Safari...
Choose Safari menu --> Preferences
Click the Security tab.
Make sure that Enable JavaScript is selected.
Make sure that Allow Plug-Ins is selected.
Next to Allow Plug-ins, click Manage Website Settings
Select Adobe Flash Player in the far left column.
In the "When visiting other websites” menu, choose Allow.