How to check the network for security?

Question

Information Security

Recommend, please, some software tools for the possibility of such a check)
Interested in the possibility of access from the outside and the presence of possible problems within the network.
I downloaded Kali, but what can I try to start with from all the huge number of progs that it contains? :)
Maybe there are some complex methods or good manuals
I would be grateful for any info

Answer 1

Basic set:
In general, look in kali linux to see what software is installed.

Answer 2

BackBox-4.5 suits me better