hey, i know i have a weak core and lower back, i was wonder what would be some good exercises to build up and strengthen my core and lower back
deadlifts and squats i'd say
i know rack deadlifts help a lot, i always have pain in my lower back/core area i want to get rid of it, i know i need to build up my core more
deadlifts and squats
You want to build your posterior chain, not just your lower back. Deadlifts and squats are great, but you also want exercises that do not affect your CNS to that extent but give you benefit. Reverse Hypers, Hypers, Glute Ham Raises, Pullthroughs, Band Good Mornings, these are all good. Good Mornings are good as well, but you are going to need to watch volume as you rotate all this stuff around.
strong abs r just as important, also, try seated good mornings in the rack...I do reverse hypers slow with weight, rope crunches, seated gm's...for power I do squats and deadlifts...
And remember that if you want to develop quality core strength, you're going to have to work your entire core, not just your lower back. Good core strength comes from strong abdominals and strong erector spinae (including lower back), among some other things. It's something that many people, including myself, have neglected or in some cases continue to neglect, so it's great that you're wanting to improve that area of your body.
Good luck with your training!