as far as the mysql user name goes just view panel > goodies > mysql. the user name is listed there. There isn't a way to get the password.
If you're not sure what the password is, but want to try a few guesses, you can allways use PhpMyAdmin for that. Just keep submitting the user Name/pass till it lets you in.
Your alternatives are:
1) deleting the user and making a new one (you can use the same name)
2)adding an other user to your database. This way your software can still connect to the database as well as you with the new user/pass.