Well, it depends! If you want your smoothie to be thicker as a shake or be thin runny liquor like a juice maybe.
To achieve a viscous blend texture, you should use frozen fruits instead of fresh ones.
Cut all the fruit ingredients into pieces and freeze for 30 minutes before giving them a blend or use packaged frozen fruit from the store.
On the other hand, if you want a smooth blend texture to the smoothie, add some water while blending.