I started playing around with a small VPS. To learn about security I followed a tutorial on Github [1] in which they talk about a lot of tools. I understand that ssh, ufw and fail2ban are the most important but for example should I use PSAD or CrowdSec?

Basically I want to self host services and run web apps, so how can I know how much security do I need?

Thanks for your help

[1]: https://github.com/imthenachoman/How-To-Secure-A-Linux-Server