Sorry, gonna have to do it in pieces because of the max character limitations of the forum. And sorry, I tried to draw up a (crude) circuit, but it turned into a bit of a mess and i messed up, didnt wanna make it any messier. Can still have another go at it if itd help, though.
But for the OLED, I have 7 pins, plugged into the arduino in their respective places as follows:
OLED UNO
VCC 3.3V
GND GND
D0 D10
D1 D9
DC D11
CS D12
RES D13
and my DHT11 is as follows:
DHT11 UNO
VCC 5V
DATA D2
GND GND