A CNA is not a nurse. A CNA is a certified nurse's aide. They do things like take VS and assist patients with ADLs. Much of what they can do is determined by the facility. CNAs at my former hospital could do little more than take VS, empty catheters and set up rooms. They weren't allowed to do finger-sticks or set up tube feeds or anything, though they are allowed to do those things in some facilities.
An LPN/LVN is a Licensed Practical Nurse or Licensed Vocational Nurse. They go to nursing school
, are required to take NCLEX and practice under their own license/scope of practice. I don't work with LPNs (what they are called in my state) so someone else will have to give you more of the specifics on what they do. But an LPN is a nurse, a CNA is not and their roles are distinct. In my state, it seems that LPNs work mostly in nursing homes or doctor's offices but there are some places where you will still find them in hospitals.
ADN and BSN are degrees which both enable the recipient to take the NCLEX-RN and become an RN. There is no difference in scope of practice between an ADN or BSN RN or even a diploma RN. All of them are RNs. I am an RN and I have never had anyone to do "grunt work" things like dressing changes or catheters for me. In fact, I'll be on my way out the door to a dressing change shortly as soon as the patient's facility calls me back.