If it asked for a password during the install, that is what you would use to login with.
Password= whatever you put as your password
And if that doesn't work or you don't remember your password you created or skipped past it, boot into single user mode and then you can change the password that way.
At the boot: prompt tyupe this: linux init 1 or linux single
Then if that works and brings you to a bash shell with no login prompt, type passwd
And that should ask you to change your password which would be for root.