There are a few different versions of this game, but this is probably the same in all of them.
On the right side of your screen, click the down arrow until you see a red gift package. It should open a window with 4 tabs at the top. The 4th tab should say wishes. Click that.
That should open a window with two tabs. For the item you would like to ask your friends to send you, stay on the "my wish" tab. You can search for the item you want or scroll through to find it.
To see what your friends have asked for (and send it), go to the "friends' wishes" tab. It will show you what they have asked for, if they have selected something.