Database configuration error?

[Crazycat]

Ok, i did. So far i got here. 

What should i write and where, having these information? Because i tried diferent combinations and i get error 500.

Seems like you try to install another instance of MyBB. You may not have well read the documentation.

Select all files and directories intended for upload from the new package, and copy them to the main forum directory, overwriting existing files.
...
After uploading and overwriting the files, MyBB may ask you to run the upgrade

[Valentin Ghioc]

Valentin, you want to update your board, why do you call install-routine?

boardurl/install/upgrade.php

and please don't forget to make backups before you start, database and ftp!

I see! Now i am here and i have deleted the lock file. 

But i still get this message. It is something what i miss?

I also deleted the whole install directory. And that message still appears.

[HLFadmin]

The lock file in the install directory prevents inadvertent installation.
You remove the lock file when you intend to install or upgrade.
After the installation or upgrade, the system creates a lock file for the reason stated above.
Deleting the install directory afterwards is suggested but not required.

If that screenshot is occurring after you have deleted the lock file and the install directory, it may be that your browser has cached the page. Clear the browser cache.

Sometimes a Softaculous installation is a positive thing.