The command to open a Terminal would be:
/usr/bin/open -n /System/Applications/Utilities/Terminal.app
I have no idea how you would open the Terminal in a specific folder. Prepending the above with the usual UNIX "cd folder_name && " does not work. The Terminal is going to open in the user's home directory regardless of the starting directory.
There is a way to do it using the GUI, right-click on a folder and you have the option on the popup menu to "New Terminal at Folder".