Certifications to get while working?

Hello!
I currently work full time in a NICU and would eventually like to go back to school to become an advanced practice nurse. I realize that is many years down the line while I get experience; however, I am wondering if there are any certifications or classes I could/should be taking at the moment. I thoroughly miss school and want to keep myself up to date on nursing education and it wouldn't hurt to earn a certification if possible during that time.

Does anyone have any suggestions

Thanks!
CCRN?
Why not get certified as a NICU nurse? There are 2 or 3 different organizations that offer such a certification.