Everyone on the interwebz that says they know something about pentesting will talk shit about nessus and say that it is for lazy pentesters, it creates too much noise, and that it produces too many false positives. That may be true, I don't know. But from a learning perspective it can be really great. It can help to show you what kind of vulnerabilities are out there. So whatever, do what you want.
Run all default scripts together with a port-scan. These scripts could possibily crash certain servers. Causing a denial-of-service. So never run this on production servers.
nmap -sC 192.168.1.101
Nmap has categoriesed their scripts into several different categories to make it easier to run a few of them together
So if you want to test all the vuln-scripts you do
OpenVas
OpenVas is another popular open-soruce vulnerability scanner.
If you are on Kali linux you have to firt run the initial setup scripts, like this
Make sure to write down the password that the initialisation-scripts gives you
This will download some stuff and start setting everything up. WHen everything is set up you go to the web-interface: