NDA Question

I have been looking to buy a small online business. Have reviewed several of them but none have jumped out at me. Question in regards to the NDA's I sign for these businesses. Does that prevent me from opening a similar business albeit without using any confidential information, products or vendors? In reviewing the NDA's it does not specifically say you cannot open a similar business just that I can't use any confidential information moving forward. Maybe I should call a lawyer on this question next but wondering if anyone has any experience here. I want to explore all legal options to make sure I am not getting in hot water.