If you do a Google search for LM747, you'll find plenty of info. The 747 is a dual 741. If you have other, more modern choices, You should use one of them instead. The 741/747 is old technology.
If you use only half of the 747, connect the unused section as a voltage follower, with the noninverting input connected to a voltage that is within the commmon-mode range. If you are using dual supplies, that voltage can be GND. If you leave the unused section floating, it can disturb the internal bias network, causing the section you are using to be less than optimum.