You can check your Visa type on your Visa supporting documents.
If you have an I-20 this means you hold an F Student Visa.
If you have a DS-2019 this means you hold a J Visa, the exact type is listed in box 4.
If you hold an I-797 this means you have an H1B Visa, etc.
Please review your passport stamp and Visa supporting documents as you will be asked to provide details about your Visa held while in the US.