Where can I find people like you who will work for free on the promise of future money dependent on a roll of the die which is funding? Please tell me. I'll take one CTO, 2 senior devs, and 4 junior devs.
Here's the deal. I don't know your situation, but you are basically saying that your time is worth $0. That might be true or it might not be. You have to be the one to decide that.
Additionally, if the company gets funded, the very first thing that will happen is you will be fired or otherwise relieved of your position and they will hire an experienced CTO who will be paid a lot of money. This is the smart money move for them and a pat on the back for a job well done is all you will be likely to get. By that time, you will have no solid programming experience, having played spreadsheet warrior for a year or two, and being at least one level abstracted away from the real work through which you would earn your bread once you leave this losing lottery ticket.
Finally, you have no experience. You might not even conceive of what this role requires. You are being asked to be a CTO during an internship. This is a glorious chance to fail. How strong are you emotionally, to face a humiliating failure? Your decisions will be picked apart and your current lack of experience will be laid bare for everyone to witness.