OK did it from the command line as per bsdtester’s instructions and it worked.
First checked that bash was there.
It was not, so I went to appcafe and installed it.
Then did the cat /etc/shells command that bsdtester showed (see above) and it responded with /usr/local/bin/bash.
Then gave the command to actually switch default shell to bash:
chsh -s /usr/local/bin/bash
At this point it responded something like user account updated. but of course you have to log out and then login again before it takes effect so I did that. Then opened a terminal and it was clear that it was now bash, which I checked with
which ps $$ and also double checked with the getent passwd ‘whoami’ line that bsdtester gave. [NOTE: which ps has quote marks on either side of it, the quote mark uner the tilde, upper left key on most keyboards under the esc key, but in this commenting system they don’t show, so I mention it verbally].
Will try out a .bashrc now and it should work.
Thanks again to bsdtester and everyone for the helpings.