Such an explanation is beyond the scope of a sentence discussion. For a start, I'd suggest that you read the Tips & Notes for the Demo skill, which you can find here: https://www.duolingo.com/skill/cs/Demonstratives/tips-and-notes.
That link just drops me on my home page. I assume that's because I haven't advanced far enough to unlock that skill.
And Boy Howdy, i need to read something, because this ten/ta/ti/to/ty stuff has got me flummoxed. (Please translate the sentence into Czech!) My strategy has been to do my best, and then write the sentence down, so the next time it shows up, I can check my work against what I wrote down. But understanding is not mine. I keep figuring it will come, someday.
The brief tip-n-trick on demonstratives in this "Plural" skill was somewhat helpful, but not completely. It doesn't even mention 'to,' which was presented in the "Feminine" skill as the/these/those, but which is used in this sentence as a demonstrative pronoun for a masculine inanimate noun 'domy'? And that 'ty' is snuck in there just to make me crazier. The tip-n-trick section also talks about lidé being a masculine plural noun, but there's another sentence in this skill set where the right answer is "Jsou to novi lidé," using 'to' which I thought was feminine with the masculine 'lidé'?
Try this link: https://duome.eu/VaclavNovak/progress.
Click on the Tips and Notes link under your user name "box", and then scroll down (it's pretty far down) until you see Skill: Demonstratives. BTW, you should be able to see the T&N for all Skills for which they currently exist. As a bonus, you can find lots of useful stuff about your work at Duo there, too.
As for to, I think what's most important to get used to are the to je and to jsou constructions. They also appear as je to and jsou to, and they will almost always be translated as "it is/that is'" for to je and "they are/those are" for to jsou. In these constructions, to is used regardless of the gender or number of the noun that's used, though any adjective that modifies the noun must match it in gender and number. Hope that helps a bit!
PS. -- There are lots of little things "snuck in there" when learning Czech... keep an open mind and trust that, with effort, it will all start to make sense... eventually! :-)