You will arrive in terminal B and clear immigration and customs. You will have to clear security again at terminal C. If you don't have a lot of carry on luggage, it's faster for you to walk to your right outside terminal B and follow the arrows on the ground to terminal C. It's a 5 min walk outside.

If your IB is late, you can ask the people working in the immigration hall to help you move to the front of the line for your connection. Remember to pick up your bag in EWR and clear customs and drop it off right outside the customs hall.

2 hours is pretty tight especially depending on time. Immigration queues can get really long even for US citizens during certain times of the day.