Hello bjzhong25,
Thanks for asking thew Apple Support Communities about Safari autoplaying your videos. I am happy to check this out with you.
For the general Safari setting, click the word Safari up top on the menu bar, then click Preferences. Then click the Websites tab. On the left, click Auto-Play. That window will show you currently open windows, and you can choose the option you want. Bottom right of the window has a section "When visiting other websites:" Make your selection there between "Allow All Auto-Play", "Stop Media with Sound" or "Never Auto-Play"
If you just have a specific website you want to do this for, you can open it, and then enable this feature by clicking on the word Safari up on the Menu Bar. Then click Settings for This Website. In there, in the middle is an area for Auto-Play. Click it, and choose the option you want.
Thanks and have a wonderful day.
