Not exactly sure which part you are at... Probably the second half of this post.
Did you launch xampp and Start Mysql
Need to start it Everytime... You can set it to start always, but I have run into issues that it does not start.
Then when you go to CMD prompt you would type
MySQL -uroot -ppassword
Where root is your user (if user was account it would read -uaccount)
Where password is your password (if password was secret it would read -psecret)
Then you can do:
use peq;
Change peq to your database name. (If you save a SQL file from heidisql from your database it will put entries in the file to make the changes to the database you pulled it from... In the event you make multiple servers and want to copy an entire table from 1 to the other).
Or what part are you at? Looks like your trying to set password after you set the path?
If so just type
MySQL -uroot
In the CMD window. You don't need to add the exact location like you did when setting the path.