@Engelbert - Becoming a research nurse does take an extensive amount of schooling. First you’ll need to become an RN (Registered Nurse) which will take you about four years and then you’ll need to look at getting a Master’s diploma or even a doctoral degree. It is in all likelihood perhaps the hardest avenues of nursing to pursue because it takes a lot of years to work your way up, but if it’s something you feel passionate about you have to be prepared to put in the work. It’s certainly challenging but hugely rewarding at the same time.
My advice to you would be to decide first of all if nursing is really what you want to do. If so, then spend the time in school to become an RN and if you’re still interested in going into research then the option is always available. Do not be concerned about your age, you’re not too old for anything.