You have a long journey ahead of you. If you are interested in the Excelsior ADN bridging program, this page contains a link to PDF of required classes: Associates Degrees Nursing | Nursing Degrees, Programs | Distance - excelsior.edu
More than likely, your humanities and fine arts courses should transfer. The only credits that I've heard of not transferring are courses that a traditional university would require labs (such as Anatomy and Physiology). Those I would suggest going ahead and getting out of the way now since you are probably already enrolled in a community college lpn program (if you have room in your schedule of course! I'm sure your schedule is already jam-packed with clinicals and nursing courses). Try and start working on your core classes now and get them out of the way and try and aim for a high GPA; this will be a deciding factor when it comes to CRNA applications/interviews.
Once you get your ADN finished, apply for an ICU job and work towards CCRN certification. Although this is not mandatory at most CRNA programs, it is preferred. If you look at current enrolled SRNAs, almost all have their CCRN. Some schools are picky over PICU and NICU, so keep that in mind when choosing a Intensive Care job. Most schools do not accept ER experience, and you will need at least one year experience ICU, preferred two years (you will need at least two years experience to become eligible for CCRN cert).
Also, think about your current life situation: married? kids? planning to do so in the near future? CRNA programs are all-time consuming, you will not have time for a family life. There are many nurses who get through these programs with spouses and small children, but they have a lot of help. If you get an interview when applying to CRNA schools, this will be a topic they will grill you over: how are you going to manage your family? How are you going to pay for this program? Is your vehicle reliable and how are you going to afford gas to get to clinicals? Is your spouse going to support you through this? What if you two decide to divorce in the middle of the program? (seriously, they ask these questions!). They are concerned with your ICU and nursing knowledge, but they also want to pick candidates that are going to make it through the entire program, since there are so little spots and so many applicants.
Hope this helps
Good luck in the future!