[Koha] How to setup Holds in Koha

Hello, We have Koha installed in our server for education purposes, everything looks fine, but there are a few issues: 1. We decided to use Hold function to reserve a book for patron. But, i.e., if there is only one book, many patrons are able to reserve a book using Hold function. Is it possible to make a book reservation only for one patron (one book -> one patron reservation; two books -> two patrons reservations; etc.)? 2. Is it possible to create automatic term for holds? I.e. reservation for the book could be made only for three days (and if you won't come to take your holding from library, it returns to library without Hold tag)? How to do it? Thanks for the help