We recommend for you to reach out to your local US Embassy to confirm the Visa type to ensure that this information is applicable to your country. The Visa Wizard on the US Government Travel website may be helpful:
Here are the recommended responses to the 2nd and 3rd questions:
Why are you traveling to the U.S.?
Study or Exchange
What will you be doing in the U.S.?
I will take a short not-for-credit course or a recreational program
If you have questions about US Visas, and for recent news, please refer to the links below:
If you require a letter from Singularity, please email Welcome@su.org