Question about allowed stay before student visa

Hello,

I am a US citizen hoping to obtain an Italian student visa for classes starting in September. I am currently applying for different schools now. 

As my partner is an Italian citizen, I am hoping to be able to visit him before classes start. I am currently in the US and have been for the last nine months.

My plan is to visit Italy March 2nd- April 2nd, and then come back on July 2nd and hopefully be able to stay until September when my classes start, as I would hope to secure my student visa during the three months I am back in the US. I have heard conflicting information after speaking to different Italian consulates around the US, some stating I'm able to enter 90 days before my student visa begins, and some saying I shouldn't visit Italy as a tourist at all, as entering as a tourist before classes start wouldn't be genuine intention of tourism.

Does anyone have any experience with this?

Thank you in advance!