How can I get Tails OS?

[usonian]

6. Very cool!

A tor browser can browse regular web addresses (https/http) HIGHLY RECOMMENDED, as well as onion addresses, which you'll rarely if ever go to.

There are legitimate sites on the dark (onion) web. Especially for anonymous tipsters and so on.

The browser in TAILS is a modified firefox to do onion browsing, so within a decibel, it's the same as the regular tor browser. (best of my knowledge)

https://www.torproject.org/

Now, the point is: What are you sharing/communicating with whom?

One weak link in your group can divulge everything, if they are threatened and unlock their phone or computer. I believe this is how most signal and other encrypted info is divulged.

On one hand, signal messenger seems the best to me for messaging (even does videoconferencing) and I am going to look into all the tools available at riseup.net.

The same "weak link" caveat applies.