Thanks for visiting the Apple Support Communities. From your post, I understand that you are having trouble accessing specific features in Control Center, like Night Shift and Personal Hotspot. I'd be happy to help!
Based on the instructions in Use Night Shift on your iPhone, iPad, and iPod touch - Apple Support , to turn on Night Shift (and other features like it), you need to firmly press and hold on the Brightness slider in Control Center. This act is more like pressing a button than just setting your finger on the display; place and hold your finger on the slider, and then push into the screen a bit.
If you continue to have trouble accessing the features you need in Control Center, try restarting your iPhone: Restart your iPhone, iPad, or iPod touch - Apple Support .
More information on Control Center can be found here: Use and customize Control Center on your iPhone, iPad, and iPod touch - Apple Support .