Rooting old Droid 1

So I have an old Droid 1 on Verizon that I wanted to see if I could upgrade to jelly bean, or at least something more recent than gingerbread which it is running. I think the only way to do this is by using a custom rom and/or rooting it. As you might be able to tell I don't know much about this, so if anyone could help that would be great! Do you have any resources to learn how to do it? And is it even possible on this hardware?

Thanks!