hi i cant find my iphone

Hi,at the first thanks for your interesting,I cant find my iphone i lose it last night,and i'll try to call but it's closed,i think that any people use it,and he closed the phone or take it off sim card,i dont have any idea,i just checked from iCloud to find my iphone,but i didn't singed in from the phone,can you help me,can i activate iCloud from my pc ? or how will i find my phone ?