Legendishaq Wapskete After adding the forum to ur site ..click on Edit forum structure >> Click on add category to add forum categories like here @Ishaqwaps forum u wil see categories like "coding helps", "Mobile/software discussion" etc..
Den after a category .. Click on add board to ..Add sub-categories like in "coding helps" category like Ishaqwaps, U wil find somtin like "xtgem, wapka and php coding helps" they are all board or sub-categories ..
Preview ur site per-content u added to see how it looks !