If i will arrive to beauvais on Saturday (september 10th), will i will find any buss or train from beauvais to Paris?

There will be TER trains from the Beauvais train station to Paris Gare du Nord, but you first need to get from Beauvais airport to the train station in Beauvais, either by taxi or city bus.
 
https://parisbytrain.com/paris-beauvais-airport-train/