To get support for using Maxima, use the
Maxima mailing lists.
Questions specific to wxMaxima can be asked (and answered!) at Github discussions.
A old forum (readonly now) exists at Sourceforge.
A lot of documentation about Maxima can also be found at Maxima webpages.
wxMaxima can use jsMath TeX fonts to display math output. The fonts are used to display Greek characters and math symbols (like the integral and sum symbols). Follow these instructions to install jsMath fonts in your computer.
Here is a collection of tutorials contributed by wxMaxima users. If you wish to contribute a tutorial, send it by email and I will add it to the list.