yosemite uppdates and prompts

i am very new to using mac book pro, and was recommmend finding on the new yosemite system that there are far too many prompts and synched uppdates etc.. does anyone know how i can do a general disabling of them. for example, i would like to remove the prompt like auto refill......when i am filing in forms for payments

and i get email and fbk uppdates when i am in other programmes....

thankyou, anna