i dont see any button

Do you see a small blue circle icon with a white looking pencil in the bottom right corner of your screen if so click on it and Draw Something and there should be like a little upload thingy just click all the buttons and it will eventually bring you to a upload page where you put a name for your post and a description for it and then you just click upload

A

yay, im on pc and idk how to post

True:)
I trust ya!