First let me say that any experience you can get in the clinical setting will help you in nursing school
clinicals. I worked as a nurse assistant for a year and then decided that I wanted more, so I began my prereqs while working parttime.
I am now 2 semesters away from being done and I took all the prereqs prior to taking any Nursing Education classes. I would highly recommend this, as it frees up your time and you will need the extra time for nursing course work/clinical prep. I have a few friends who left their electives until now and are taking them during the summer, that seems to work well also.
I did have classmates that didnt get those harder prereqs out of the way (A&P, College Algebra, Chemistry) and they are no longer with our class. It was a hard juggle for them or they didnt pass their classes. I am sure there are those that do well juggling all this and the nursing education classes...but why stress yourself out if you dont have to!!
As far as nursing assistant title...do you mean job description or responsibilities? They vary from place to place. You will be involved in a lot of patient care (bathing, vital signs, ambulating, etc). I think it is a great start for a nursing student, it gave me more comfort in the clinical settings at school. I wasnt as nervous with the patients and could focus on the tasks at hand.
I would also recommend going for the RN, its an extra year but will be worth it for you
Best wishes to you!