Good suggestions from Laurel.
If I remember correctly, the OP has already been to Venice and didn't care for it: said it was so crowded that it scared her. At the same time, Vero, you don't want to stay in isolated places, such as an agriturismo in the countryside, right?
Additionally, Vero, you didn't like London (why?) and "do not like places like Irland" (why?) You don't like "crowded places with long lines." It might be easier for people to make recommendations if you could give us some examples of places you've traveled to that you did enjoy and why? Understand as well that you're going to be traveling during high season, and to some of the most-visited locations in Italy so lines and crowds are simply going to be difficult to avoid at times.
This concerns me:
"...my trip is in June. 25 days .But Im not worry about accommodations, Im sure I will find a place to sleep...!!!" Budget is between $100 and $200. Did you mean in euros or Argentine Peso?. Or a different currency? This from a previous post:
Im also traveling from Argentina and I will like to pay on the hotel
since currency exchange is not favorable for me to pay in advance when
booking from my country... I will need to pay in hotel at check in.
I'm a little confused why the exchange rate would be any different if booking in advance than booking when you get there? Not, of course, that you have to book anything requiring payment in advance but the exchange rate is what it is if that makes sense?