Are these short sentences correct?

They are not good English. There are several unnecessay words, and the word order is incorrect.


The word "simply" should not be the first word in a sentence. Here, it is not necssary, it does not have any useful function.

"Look up" is normally used only when you are searching for a special piece of information. "What is a 'hovercraft'? - "I don't know. Look it up on the nternet.". Otherwise, we would usually say merely "I will look on the internet."

"What" does not need the word "all" attached to it. (it is not ttue, You can never find "all" that is available !)

Similarly, the word "there" is quite unnecessary. The only useful words you need are ". . . what is available".

The best sentence would be

"I looked on the internet to find out what is available."

They all sound forced, though an English speaker could probably work out what you are trying to say. I think you want to say "I simply looked on the internet to see what is available there." or "I simply looked to see what is available on the internet.".

yes