I have just installed Ubuntu and I am not sure what my password is. I don't really know that much about computers.
Do this, boot into recovery-mode. to do that, press shift at the purple screen. Then a menu should come up and from there select recovery-mode. Now a ton of text will apear, but then another menu will apear. From there select root command line or something like that. Then I think you can just type:
and then type in your new password, when you're done, type
and boot normally.
If you run into an "Authentication token manipulation" error, then you first need to type:
Then do the
You have now changed your password.