I've solved it
I've deleted all the sql server files, checked if the service was running, installing it on another partition... none of it worked
What worked for me is, from the SQL installation center selected new sql standalone installation, and on the server configuration page, changed the account name to "System", following the instructions from https://support.buildsoft.eu/knowledge-base/sql-installation-error-could-not-find-the-database-engine-startup-handle/. After that, Every component from SQL Server Express was installed and I was able to connect from the management studio to the database engine service.
Thanks for the help!