ABS light on

[dillpickle505]

I have a 98 chevy 1500, my abs light has been on since i bought it and if i pump the brakes they vibrate hard. There is also a screaching sound on my passenger side when driving. does this sound like a sensor? or a bearing in the hub? i have read lots of things but not sure where to start.

The owner before re did all the brake lines and looks like front and back brakes are pretty new.

Any advice is greatly appreciated!!