If your using the default version of Puppy 4.2.1, it should have a console icon right on the desktop. If it doesn't look for either console or terminal in the menus. I've used this version of puppy a lot and I know the default version has a terminal option available. If your using a modified version, they may have hidden or removed it.
If necessary, you can type CTRL-ALT-BACKSPACE to kill the graphic interface to get a console, then type xwin to restart. Or type CTRL-ALT-F1 to get a terminal, then CTRL-ALT-F5 to get the GUI again. (I believe on this version of puppy, the GUI is CTRL-ALT-F5, could be F4, F6, or F7, just hold CTRL-ALT down and cycle through the F keys.)