Hi VinnyB
About the font: most browsers have a zoom function
usually with the shortcuts Strg+ and Strg-
I doubt u have MySQL version 7.x since such a version never was released (they jumped from 5.7 directly to 8 ), so my guess is 7.x here is your PHP version which most probably got nothing to do with this issue. Also the version of your Joomla is probably a typo. We currently have 3.9.13
For installation of jOpenSim, the basic component (com_opensim.0.3.1.5.zip) is a good start, but the package (pkg_jopensim.0.3.1.5.zip) might be the easiest way since it installs all modules and plugins as well in one go.
Back to your "1000 bytes" problem: the link provided is similar to what I asked before (default storage engine?) but without further details everything is just a wild guess.
Do you have access to the joomla database (e.g. via phpMyAdmin)? What tables can you find starting with #__opensim_* (replace #__ with your own joomla prefix).
Suspecting your database server has an issue creating some index, we could maybe find the one causing it since this table and all behind it should be missing in the database.
Greetz
FoTo50