The toilet valve knob has issues. I can't turn off the water to the tank. Neither can I increase the water flow to the tank. The knob just turns without any real resistance. Should it be replaced? Also, the water level in the bowl is significantly less that what is "normal".

When turn knob does spindle attached to knob turn? If not then angle stop needs replacing.

What type of ballcock do u have. Check pic below.

Chuck

https://www.askmehelpdesk.com/attachment.php?attachmentid=32393&stc=1&d=1281279612