Not to be mean, but, English isn't your native language is it?
You post seems pretty straightforward so I think I understand your question.
If you have the gear for both specs like you say, I'd advise trying both and see what you prefer.
Otherwise just go with what suits your play style the most. If you like casters in WoW go Balance. If you like melee in WoW go Feral. Feral has perhaps more utility but Balance has higher damage output and those nifty trees.
There's nothing else anyone could say about this. It's only up to you to choose. If you don't like what you chose just respec, you can't expect perfection from the first try. Lots of new Druids like you recently started asking which specs and which talents and blah blah blah. You need to experiment if you ever want to "master" the Druid class.