1.How can I set the font and size of the TTYs?
The command:
dpkg-reconfigure console-setup
allows me to choose certain fonts/sizes that cannot be installed (an error message appears after the reconfig. process). Moreover, the values set in /etc/default/grub
alter everything. Sometimes you are using a font, but after rebooting it is changed.
2.How can I know what font/size is the console using in a certain moment.
There is a how to in the community pages to set the TTY resolution but it has no description of its interaction with the font/size of the console during boot and after.