Hello Can i reserve GMC Acadia on 1 April to 10 April in Los Angeles....?

Go to the website and arrange the vehicle you'd like

Yes ...but they rent cars available at moment you arrived... Maybe other car better

Use their website to book a reservation for those dates. They do have Acadias.

You can check this using their site. Via Google Maps you are only in contact with people who know the location. It is not certain that they are employees of Sixt. I am not for example. So just have a look at their site, or send them a mail or call them. That will be the best ways to make sure that you can reserve the car you want.