I do agree with the previous response. With just the Associates you can start to work in the field, but you have to take into consideration the long hours of a Nurse and having to go to school. I currently have students that have gone for their Associates first and are now working on the Bachelors and it takes a lot of self discipline and time management to do both. There are some Bachelor in Nursing programs which require you to have your license and an Associate in Nursing. For example at the CUNY School I work for (CUNY SPS) we have a Nursing program which requires that students have their license and have their Associates. (Here is the website for you to checkout, https://sps.cuny.edu/academics/undergraduate/bachelor-science-nursing-bs).
However, at CUNY Hunter a student can apply for Bachelor in Nursing without an Associate or license (Here is the link for you to explore, http://www.hunter.cuny.edu/nursing/admissions/undergraduate/bachelor-of-science-nursing-program), but the students need to meet the prerquisites of the Nursing major and apply to the Nursing program to be able to declare the major.
There are some Associate Nursing programs which have what is known as articulation agreements with 4 year universities. If you are in one of these programs, you will have an easier time transferring credits to a four year university.
There are a lot that goes into making the decision of Bachelor over Associate. Time, money, and even the admission process should be taken into consideration. I gave you two examples, but I recommend that you look at various nursing programs, and speak to the nursing department of the school(s) you are interested in. The department will be able to give you advise from individuals who have worked or are currently working in the field.
Hope this helps. Good Luck!