Welcome to Macaulay2
Try entering '2+2' at your next input prompt, which begins with i. The two output prompts begin with o. The first one, with the equal sign, '=', gives the value computed from your input, and the second one, with the colon, ':', tells what type of thing the value is.
Type one of these commands to get started reading the documentation:
To read the documentation in info form, in case you happen to be running Macaulay2 in a terminal window, replace help by infoHelp in any of the commands above.