Trisquel mini
When was the last update for trisquel mini 8?
Also is there a section that shows updates?
The different flavors of Trisquel are different sets of packages that come with the default install. All those packages are in one single repository. All of them are updated whenever severe bugs (usually vulnerabilities) are fixed. You can run the "Update Manager" to check for updates available in the repository. However, unless you specifically asked to never automatically check for updates (in the "Updates" tab of "Software & Updates"), it should be automatically done weekly (or maybe daily). New versions of the packages (as in having LibreOffice 6 instead of LibreOffice 5) will all come at once when you update to Trisquel (Mini) 9. In other terms, Trisquel is a stable distribution.
Where can I confirm updates? How do I know I didn't install a malicious update? I just want to know when the last update for trisquel mini was.
Again: Trisquel Mini is a set of packages, which are individually updated whenever needed. You can look at APT's history if you wish (APT is the package manager): it is in /var/log/apt and it is timestamped.
There is no easy way to identify malware. Even given the source code. A mere bug may introduce a severe vulnerability, which allows an attacker to execute arbitrary code. Only installing what comes from Trisquel's repository is the best you can do. That repository only contains free software (a requirement to trust the software) and APT is secure: https://wiki.debian.org/SecureApt
Auditing the source codes of every program you want before installing them from these sources is impossible for a person alone (one single program may "weight" millions of lines of code). If you are a programmer, you can do it for a few programs (or pieces of them) though. 'sudo apt-get source' allows to easily download the source code used to build a package. But for the operating system as a whole, you need to rely on the rest of the community. We collectively control the software.