Auth noob some advice

Thank you all,
For now I've tried Ion Auth with no result =(
I just make a copy of my app, install all the files as the author said, rename
models/ion_auth_model.php => models/Ion_auth_model.php
controllers/auth.php => controllers/Auth.php
upload the sql to the db
and if I point to localhost/app/index.php/Auth or localhost/app/auth i have 404 =(
I'd just like to see how it works for studing =(
then I will try petrinze code to see what's happening