Welcome and welcome to a the world of BMW tinkering and fault fixing, in my experience BMW's love to throw up a warning light, my old E39 was like Wac-a-mole, put one out and another would appear - however most of our cars are over 10 years old so got to expect some trouble!!.
ABS pumps can be very expensive to replace if you buy a new part from BMW. A lot of people send them off to ECUTESTING to get them refurbed at a much more reasonable cost although not all modules can be repaired.
If you have the 3 lights (DSC, ABS and handbrake light) it might be just the high pressure brake sensor (there's 2 of them top left of engine bay) which is very common. Appeared on mine after 1 week of ownership, this part is about £90 from BMW.