Can’t find control center or restart on apple watch
When I press the side button, it shows my apps, when I press and hold the side button, I just get Siri. touching and holding the bottom of the screen on my watch does nothing.
Question marked as
The other button. Not the Digital Crown.
Quick press and release the flat oval side button will bring up the Control Center, that has the Water Drop icon, the iPhone Ping icon, the battery charge information, Theater mode, Alarm disable, etc... (see picture)
hUse Control Center on Apple Watch - Apple Support
DO NOT hold the button, as that will bring up Emergency Services display. Then again, if you want the power button, it is on the Emergency Services display, so in that case press and hold the flat oval side button.
Settings -> Accessibility -> Side Button Click Speed
will allow you to adjust the timing for the press and release so it can be done reliably every time for you. This option is also very useful for Apple Pay's double press and release timing. I like Slow, and my Wife likes the Slowest setting.
This page may also be useful:
What’s new in Apple Watch and watchOS 10 - Apple Support