Advice on CNA to LVN career path.

Hi I am interested in becoming a LVN and am considering going through a CNA program first. Is it a good idea to start at the bottom and work my way up?? Would it give me some general skills to help with the LVN lateron?? I just want to make sure that nursing is for me. THe only thing holding me back is that I tend to have back problems from time to time and am not sure whether or not that would hold me back. I am a very caring and compassionate person who wants to make a difference. I live in College Station Texas if thats make a difference. Thanks in advance!