Hello! How can I do to put a square somewhere on the screen of my 3d world (will stay there forever, I will use OrthoView for this) to show a different part of my 3D world in this square? Ps.: Will be good to show that different part of the world "strched" in that box. Plzzzzzzzzz Thank you!!!

Either render the small view to a texture and then render that texture to a polygon(do this if you want to move that square in 3d).

Or use glViewport and first render the large view over the whole screen, then set glViewport to that small square and render the scene again from that point of view.
Lesson 42 is a good tuturial to look at

---------------------------------
For an overdose of l33tness, flashbang.nu