Standard options have a multiplier of 100. The Feb $5 put that you highlighted has a bid of $0.22 and an ask of $0.24 so if you buy one contract, it will cost you $24 plus commission. You can buy as many as you like. Anyone who wishes to sell this option at the market will receive $22 per put.
You can bid or ask for a better price but since the B/A spread is narrow (two cents), there's not much to be gained if you get a better fill. Trying to split the B/A is more relevant when the B/A is much wider.
If an option is one cent or more ITM at expiration, the Option Clearing Corp (OCC) will automatically exercise it whether you are long and short. This is called Exercise by Exception. For equity options, you'll end up with a position in the underlying (long or short, depending on whether you were the seller or buyer). Index options are cash settled. A broker's threshold for such automatic exercise may not be the same as OCC's.
If you are long the option, you can designate to the OCC via your broker that your do not want auto exercise at expiration. This would make sense if they it's ITM by pennies and your commission to close the position exceeds the aggregate ITM amount.
Since your put costs $0.24, SNAP will have to be below $4.76 at expiration to profit. It will be profitable much sooner if SNAP long before then. Do not think of this as a buy and forgetaboutit position. If SNAP were to drop to $5 in 1 to 30 days, you could have anywhere from a double to a triple on your bet.
Though not listed in your charts, this Feb $5 put has a delta of about 17. Delta can be used as a loose approximation of the likelihood that the option will be in-the-money at expiration. At 17%, this position is rather speculative. If SNAP drops well below $5 by expiration, you'll feel like a Conquistador but if above $5 at expiration, it will be more like A Whiter Shade of Pale.