Blood: Blot up as much as you can, using a white towel. Spray a small amount of regular household ammonia then blot again. Continue with step #3 above.
Candle Wax: Scrape off as much as you can (use a rubber spatula or the back of a butter knife so you don’t damage any carpet fibers). Place a paper bag over the wax and an old rag on top of the bag. Using an iron on low, go over the rag repeatedly. This will cause the wax to melt and get absorbed by the paper bag.