Hi there,

In order to connect to the server using FileZilla, you could use SFTP rather than FTP. You can follow the steps here on how to do that:

https://docs.digitalocean.com/products/droplets/how-to/transfer-files/

For modifying server files like php.ini I would recommend using SSH and a terminal text editor like nano or vim. If you need to do that, you could follow the steps here on how to connect via SSH:

https://docs.digitalocean.com/products/droplets/how-to/connect-with-ssh/

If you are not familiar with the Linux terminal, I would recommend following the steps from this tutorial here:

https://www.digitalocean.com/community/tutorials/an-introduction-to-the-linux-terminal

Let me know how it goes!
Regards,
Bobby