You've got some good stuff going on here but have to deduct a point for mould lines. I think your horse would have been better with a brown theme but thats me. The gold and blue armour looks good.
for a first, this is not bad at all. Your photo lighting needs a bit of work and I am not sure about the blue shadows on the skeleton horse, but I like the overall feel. Give the base some depth with a brown ink (very dilute) wash and some light tan drybrush for highlights.