I’m still having trouble with the, “Lord, I am not worthy that Thou should enter under my roof, but, only say the word and I shall be healed,” so, I mouth this in English. I know I’ll get it one day, though. “Domine, sub … anima mea.” Wait…that’s not translated right.
I wondered if I was the only one to have a problem with that. My parish has a “program” for the EF Mass that has the chants (Gloria, Credo, etc.) in it, so all we have to do is follow along. But even looking at the words for the “Domine, non sum dignus…” I still have trouble. I think they say it too fast for me, and by the third time it has turned into a tongue twister.

So for me, it usually ends up like this:
Domine, non sum dignus, ut intres sub tectum meum: sed tantum dic verbo, et sanabitur anima mea.
Domine, non sum dignus, ut intres sub tectum meum: sed tantum dic verbo, et sanabitur anima mea.
Domine, non sum dignus, utu res subadub tata verbo abadaba anima mea.
By the time I was born nobody was teaching Catholic children Latin any more. I took a year of (classical) Latin in high school because I thought it made sense for a Catholic to know some Latin. I don’t remember anyone agreeing with me about that at the time.

That was a good many years ago–maybe it is different now.
If you don’t want to buy a missal (and they are expensive) you can find a lot of information on this web site:
sanctamissa.org/en/
It’s easy to get lost if you don’t have anything to follow along with.
Best of luck!
–Jen