Interest for private loans (help please)

I'm in a bit of a precarious situation here and was wondering if anyone could offer advice or answer my questions.

I got into a t14 but will need to take out private loans to afford COL and a small portion of tuition. The problem is I won't have a FICO score until the beginning of September at the earliest. My parents have agreed to cosign for a private loan paying off the amount due when school begins for like $2k in tuition and the first two months of rent and food and whatnot, but for the rest of it they expect me to take out my own private loans to afford COL once I get my FICO score. As far as I can tell from my research online, as long as I continue paying off my credit card balance immediately and keep my utilization rate low (this won't be a problem), I should expect to debut with a FICO around 750.

Can anyone confirm this is true or false regarding my FICO score expectations, and what interest rate should I expect when I do get my FICO and start pulling loans for cost of living assuming my score hovers around 750 (a rough range is fine since I know it varies a lot)? I'm terrified at the thought of randomly debuting with a shit credit score and not being able to take out private loans or getting quoted 15% after I've already paid tuition and I'm living there since it's on the other side of the country.