No. Oppo A37 does not have a fingerprint sensor.
OPPO A37 has 5-Inch HD IPS display which works with 1280 x 720 Pixels resolution and produces 294 PPI. The display supports up to 16 million colors and the aspect ratio is 16:9 with 68.05% display area. The phone do not look big in your hand and you can use it with just one hand, even the size is 5-inch. It has Corning Gorilla Glass 4 protection against scratches.
No. OPPO A37f do not have fingerprint sensor.
Technically, Oppo A37 has all the necessary hardware which is essential for Android 8 Oreo. But Oppo has not yet released an update for the same. Until the time, Oppo does not release an update for Android 8 Oreo you cannot upgrade it.
Once again Oppo has presented us with a device that is functional, to the point and performs just as expected.