Wonder if there is a manual type text that shows step by step guide
Isn’t there a difference between a fully live installation on the flash drive compared to persistence? I sometimes would need to add drivers and would a persistence allow it? Depending on the courthouse I might need to add a printer driver.
Strictly speaking - yes - because persistence implies a read-only host.
But it is possible to install Manjaro to an USB - but doing so requires you to use the terminal as a default Calamares install will 1) refuse to install to removable media 2) not get the bootloader right.
I’ve marked the below answer as the solution to your question as it is by far the best answer you’ll get.
However, if you disagree with my choice, please feel free to take any other answer as the solution to your question (E.G. @BusinessOrc 's response or even remove the solution altogether: You are in control! (I just want to avoid even more subjective opinions being posted and confusing you even more)
P.S. In the future, please mark a solution like this:
so that the next person that has the exact same problem you just had will benefit from your post as well as your question will now be in the “solved” status.