https://www.hashnest.com/ is legit since they are owned by bitmain (antpool) but i don't suggest trying cloud mining specially now because the difficulty is very high and the chance of you getting ROI is almost zero
I can see on their site that all their mining power is sold out. (I'm not registered and that's what I can see from visiting the site). Is that correct?
Yes their "shop" is sold out, but you can buy from the "market" link on the website.
Current price is 0.000068 or so. Multiply by 12500 and that is the same as buying "One S9". from the "shop" - except the price will work out to be something different due to market demand. (and also reflecting the fact that they are presently "sold out" at the shop - so this is the only way you can buy in)
To get your head into it, go buy some tiny quantity and watch it for a few weeks and you'll eventually get up to speed and can figure out what is what.
It's fun to watch and I'd say it is a good hobby.