1. When I installed Xubuntu onto my spare drive, I put in my username and password, and go to log in onto xubuntu, it says I put in the wrong password. When I tried to change it, it doesnt work (or I'm not doing it right

2. I have an Acer Aspire One laptop, and I want to run Xubuntu on it via a flashdrive, but when I try to boot it with the flashdrive, it doesnt work, how do I force it to boot through the flashdrive?
Help would be greatly appreciated dog *cough cough*
EDIT: should I try reinstalling on my main computer to change my username and password?