Want to know do they always have to pull some teeth out before braces ?

Nope: Extraction of teeth is determined on a case by case basis by your orthodontist. Many factors are taken into consideration, including facial profile and the amount of room available in your jaws for the proper alignment of your teeth. Speak to your orthodontist regarding what is best for your situation.

That depends on your: Particular situation and age. If its a moderate to severe crowding issue and you are an adult then most likely yes. If its a child, sometimes palatial expansion and other expansion devices can circumvent the need. But always best to be evaluated by your orthodontist for your particular situation. Hope this helps.