Which is the best configuration for discourse :
www or non www ?
Ssl or non ssl ?
I mean best way for your forum , google , robots , seo etc .
There’s no clear cut answer for www vs non-www. The only decisive answer on that one is “it doesn’t really matter”.
As for SSL, obviously you want it if it’s easily obtainable for you by means of technical know-how or spending some money on the problem. Can you get by fine without it? Yes.