Hi,
It’s extremely difficult to make a diagnosis online without examination. Hence, I’ll suggest you to consult a urologist for the same. A slight curve of the penis is normal, however, if the curve is marked and is associated with pain, then there’s a possibility of peyronie’s disease which needs to be ruled out. It’s difficult to suggest any positions for doing the sexual intercourse without examination. However, the standard missionary position should be okay. I sincerely hope that helps. Take care.