Type "debug1 1" at the console. You can also use "sv addbot" to add bots. They certainly won't help your gameplay testing, but sometimes it's useful to make sure you don't have any spawns in the wrong bases or anything. To add weapons and such, there are several entities: weapon_pballgun, item_pballhopper, etc. See the entity list in the docs page for more details. It's outdated, but it should get you started.