How to add space and new line?

[ggunti]

When I type something like: "Let f:R->R, f(x)=x^2+3x+2", I am not able to add the space character (" "). Nothing happens when I press the space button. Same thing for the ":" character.

Also, I am curious if it is possible to add new lines? Let's say I want to go to next line to write something else, it is possible somehow? I tried to press the enter button, but no new line was added.

Thanks