Would a member of your site want to list of "My favorite teachers"? When using "WP Favorite posts", similar thing is possible.
There is a function by which an administrator pretends a teacher and a member in OLB, but then reservation operation can't be performed. When using a "User switching" plug-in , an administrator can also do reservation operation for a member.
A popular translation tool may be "Poedit", I am using that, too.
In others, "Loco translate" plug-in seems very easy for a webmaster.
I tried use of "WP-Members", where OLBsystem is installed.