Installing Kali via USB Encryption and More

Hey fellows,

im new to the Forum and im currently installing Kali on my notebook, but i got some questions.

As far as i know there are atleast 2 ways to run Kali, as an installation on your HDD or as USB powered live version. Im not sure wich one i should use but i guess installing it on the HDD would be the best.

Second, is there a way to encrypt the whole system and clean the RAM after working (like parrotsec)?

Uhm yeah and because its my first post here a friendly "Hello World" to everyone!

-Kitsune The Fox