install prestashop in shared hosting

[sof613]

im trying to install prestashop on my hostgator croc package where i already have 2 other sites and when i get to the install step , it tells me error no such directory . i install it via ftp into my homehtml folder under that domain , but i think im doing something wrong , since i have shared hosting . can someone please tell me what i should do and what folder to create in my ftp . thank you very much