Ok, here come the most important corrections
Cercavo una conversazione in cui si può parlare italiano, ma non potevo trovarla.
better:
Stavo cercando un topic in cui si può parlare italiano, ma non sono riuscito a trovarlo.
Learners tend to over use "potere" and underuse "riuscire", "sapere" and "essere capace/i di" as verbs expressing capability. "Non potere" is almost a thing about ethics, moral stuff.
"Non potevo perdermi quel concerto" = "I couldn't live with myself if I had missed that concert"
"I can't see anything" = "Non riesco a vedere niente" ("riuscire" is for something happening in that moment)
"I can't understand what he says" = "Non riesco a capire quello che dice"
"Can you speak French?" = "Sai parlare il francese?" ("sapere" is for "intellectual skills")
"Can you drive a truck?" = "Sei capace di/sai guidare un camion?" ("essere capace" is more for practical skills in general, not so much tied to a specific moment)
Io sono di Danimarca e la mia propria lingua è danese
Io sono danese e la mia lingua è il danese.
Countries tend to have the article in Italian. La Danimarca, la Francia, la Svezia. Island countries or very small countries are exceptions. Cuba, Cipro, San Marino, Andorra. But not always: il Lichtenstein, la Giamaica, l'Islanda. Same for languages, always with the article.
Accents at the end of words, when the last syllable is stressed:
Italians are very rubbish at this too, even in an age of intuitive writing. Four of the five vowels have only ever the grave accent, the one like this \ : à ì ò ù
E is the only one that can have both acute and grave, but the grave only appears in 4 words of common use: è, cioè, tè (tea) e caffè (coffee).
ALL the other instances (perché, finché, those passato remotos such as poté) all require the acute accent.