Have a look at the Tips and Notes for To Be-Singular and To Be-Plural. (I think these are only available on the web version for now, though.) Or you could click the link for 12. Irregular Verbs here: https://en.wikipedia.org/wiki/Czech_conjugation.
In the rest of the course is "to" translated as "that".
Nope, even in the very first lessons we have To je/Je to as This is/That is/It is.
When it's actually a demonstrative modifying a noun, such as "to dítě" or "to pivo", that yes, that's always "that" or "the", never "this".