Because prepositions (pre-positions) are confusing in any language, even our native ones sometimes. In this sentence, "para" means "to" so we are looking in the direction of (towards) our house.
In any case, in English, "I look my house" does not work. It needs some sort of modifier to explain what, I look "to" or, "at" or, "for" or, "from" or, "above" or, "below" or, "under" or, "around" or... there are over 100 prepositions and several more could work here (but not all).
However, some sentences could be quite changed by the lack of a preposition such as, "I hide my bushes" vs "I hide in/behind/next to my bushes".
And you are not "confusing" but you might be "confused" which we often are when learning new things. :)
If I may ask, what is your native language?
"Olhar" is what we do with our eyes, "aspecto" or, "semblante" or, "aparência" or, "estilo" are more in line with what you are presenting.
Remember, languages do not always translate word for word. I find this website to be very enlightening: