If you have no preferred pronouns, just say (none) or something
This will help make people feel more comfortable in this comm and has a side effect of showing you support trans people when making comments in other communities. It will also make reactionaries seethe and make it easier for mods to purge them, and make trans people feel safer all over the fediverse.
The displayed username is different from the internal one. Im mathemachristian@lemm.ee but once i figure out how to do this it will display me as mathemachristian (he/him)@lemm.ee but internally refer to me still as mathemachristian@lemm.ee
edit: got my accounts mixed up but the point is the same
Display names can, by default at least (on hexbear its 80 I think), be at most 24 chars long