First job help?

Hello, 

I am a new nurse who is looking to start their first job. I recently interviewed for two different jobs one which I kinda had a feeling I could get at a Senior Living Facility and one which was a little more out of reach for me at a rehab hospital. 

I accepted the Senior Living Facility job and I just heard back from the hospital job that it is willing to offer me a job there too. I am at a complete loss because the hospital job would be so worth it since it's a new grad residency program and I think I can learn so much through it. However, I think it would be horrible for me to decline the SLF since I already accepted and started the process of being a new employee. 

I am having a hard time deciding what I should do. Should I decline the SLF job since I've never had a job before and heard that this is very challenging for a new grad nurse or should I decline the other offer?