You will have to have the local power company install the correct service to the meter and an electrician install the service feed to the service panel(breaker box). 100 Amp is minimum. Consider 150AMP for just a little more money, even if you don't use the spaces.

Help us a little please.

Requirements for 100 amp service to what? A main service panel in a residence, a separate shop or garage.

How do you know 100 amps will be sufficient? Did you have a calculated load study completed by a licensed electrician?

What are the requirements for a 100amp service?What do you mean "requirements"?