No idea if this is a managed switch or not.
Maybe the answer is 'yes' for unmanaged switches, 'no' for managed switches?
Generally right. Also just because a switch is CAPABLE of being "managed" doesn't mean anyone configured it.
You need to get the manual so you can figure out basic commands, and then log into the device and capture the configuration, to start this process.
If the switch never had anything configured in it, even a so-called "managed" one, putting another in would be a simple swap. If it was configured to be broken up into VLAN's or has trunk ports to another switch, or happens to be a really "smart" device that's also a layer 3 router, etc etc etc... you'll need to do that to the ports on the new switch. You need the config out of it to know for sure what "jobs" it's doing and how it's configured.
You could also run into things the person who set the previous one up had to do to make something "behave", like forcing a particular port to a specific duplex or speed because of some hardware incompatibility or other problem. Those would also be captured in the old configuration.
First question: I assume they believe the need a new switch because you've run out of ports. Have they truly utilized all physical ports on the switch with ACTIVE connections, or could re-arranging cabling and making some Ethernet drops in the building be "non-functional" get you to where you could handle all of the active users expected? (Of course, there's other reasons you may have decided they need a new switch, I'm just assuming physical port density is the problem you're tackling.)
What brand/model of switch is currently installed, and is it a stand-alone, or are there other switches connected to it? How many users? What speed are you attempting to run on the local LAN? Is the cabling up to changing the speed (as in, if the old switch is 10/100, and you install Gigabit, is your cable plant ready for that)?
