Practice being the kind of person who works with computers, and someday that s just who you will be. I am one of four librarians in the firm, and the other three have all been in the field quite a while. I particularly admire the head librarian, who not only seems to know everything there is to know about research, but also keeps up with technology, substantive law, and the concerns of my own area. It is very encouraging to hear about your excellent situation and the great opportunity it is offering you. Not everyone who becomes a technical services manager in a law library is necessarily happy about it or good at it.
People get into positions in all callings by accident or unusual circumstances.
It is much more preferable to pursue a goal because you are attracted to it. So, watch and learn, first of all. A good manager will teach you every day by helping you to do what you are supposed to do. When she elicits good work from you, try to understand why it happens. Most of it will be because of your own good qualities as a worker, but some of it will have to do with the way she represented the work to you and guided your performance.