You can go anywhere with real time projection.

But, instant travel to unknown locations is difficult unless you have some association, like a person or a monument or etc.

Using a picture can shift you into an illusion.

Trial and error is the best way.

As for your second question, filling your mind with imagined unicorns is a good way to push away negative imagery, whether this comes from the subconscious, the environment, or negative spirit influences.

You will find that the quality of what you see and hear have residual effects on the subconscious mind. For example, watching horror movies all day will tend to put images and scenarios in the subconscious mind that will surface during meditation and dreaming, and in random thoughts.

Feeding your mind good quality information will in turn have positive and uplifting effects.

Affirmations are a good idea, too. They will help to banish negative imagery.

Affirmations are the most powerful tools we posses, with which to make changes.

robert