How to get to San Diego from Tijuana ?

Hi, im going to tijuana mexico for vacation and i also want to go visit sea world in san diego during my stay so im probably going to take a gray line bus and i want to know what do i need to cross the border im not a us citizen and all i have is my french biometric passport do i need to do an ESTA to get from mexico to the us or do i need a visa or do you you think they will just let me in with my french passport ? PLS REPLY thank you