Thanks to the cases, Latin is a very specific and precise language: it's rare to stumble upon some ambiguity.
But yes: many times, cases may have the same ending, and this could actually cause confusion. It is normal. Context is the key word here. By experiencing this beautiful language, you will be able to smoothly distinguish cases.
"in Italiam" is "to Italy" (because than's an accusative here, and not ablative)
2nd declension
The first class of nouns is almost completely composed by feminine nouns, whereas the second one by masculine and neutral.