I'm not 100% sure if this is correct or not. May someone lead me to the right direction thank you !!!
As far as the supplementary PCIe power cables go, that looks right. The 6 and 8-pin connectors are both keyed to fit in one way.
Outside of what's clearly shown in the picture:
Assuming your PSU is a quality unit and appropriate to handle the load of your system, you should be good there.
The image doesn't clearly show whether or not the card is properly seated in the slot. In general, if the connector is visibly in the slot and everything worked out with screwing in the bracket and securing the slot retention clip, you've done all you can to confirm that it's seated properly.
I'm not sure if it's blur from the image or not, but there may be some plastic film to remove from your card. If this is the case, I'd recommend removing it, just in case it ever comes off and gets in the way of your fans or heatsinks.
Thank you very much