show arp should not help you as this device is a layer2 switch.
show cdp neigh should help you only if CDP is running on both this device and the other end
show mac address-table should help you, giving you at least one mac address seen on the other side of this link.
By trial and error you should be able to find the MAC address of the other side of the link in the mac address-table of this device. To get the mac address of an interface, use show interface.
While doing this, please document all the links, by doing a documentation you will never have to do this again. Easiest way is to track the cables.
Side note: I supposed the port is up/up.
Another trick you can use it to put the port in 10MBps and check the other switches for a 10MBps port. Or half duplex can be used also.