How do I say the following in Italian, please?

#2 is correct!
for #1, you can say "vorrei comprare due biglietti validi per due giorni, per favore"

Hope this helps!
Erika

Thanks, #1!!

Btw, how do I order at an aperitivo? Do I just order a glass of wine and then help myself to the food? And after 1 or 2 hours, I just telll the staff what I ordered and pay?

#2 is pretty much what I'd say. Even with a bit of error, they'd understand you.
Nice 1.

OP, a two-day pass (for public transportation) is called a 'bigiornaliero' in Milan, but if you stick to a 'biglietto per due giorni' you are going to be understood throughout the country.

As for ordering an aperitivo, that again depends on where you are.
In Milan (but this is spreading all over) it is understood that if you sit down during the 'happy hour' (typically from 6 to 9 PM or thereabouts) you will pay (a slightly inflatd price) for one drink and help yourself to the all-you-can-eat buffet.

Thanks for the replies, everyone. The phrases in OP and #1 worked fine, the locals were patient with me when I attempted to buy those tickets.

Unfortunately I did not get to try the aperitivo. Maybe next time.

Grazie mille. Bourna giornata!! ;)