NewInstall but can't log in?

So new install Version : 3.6.15 when going to log in to admin, my screen flashes to the admin page then returns to the log in page. after about 9 or 10 installs, using softaculous, I logged in once and at the top of the admin page was a banner stating updating language file, I let it go for maybe 15 minutes but that was it. and I couldn’t do anything else.
any idea’s.

thanks for any help