viewport rotating in orbits and if I delete all objects still continue this. when I zoom viewport is fixed but when I zoom out viewport again rotating in orbits. how can ı fix that ? please help me (ı am sorry for my english. I am not native english speaker)
Welcome 
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I’m not sure if i understand this… you may have a look at Blender Preferences-> Navigation → Orbit & Pan → Orbit Around Selection to select your favorite behaviour ?
These are the settings I use, unless until I am working on a model then I will change the transform pivot, usually to Individual Origins or Active Element.
HINT. The closer the cursor is to the point of Transform the more control you will have on navigation!