You can't get it because it's not there.
Circulating supply is total supply minus tokens that are not circulating. Tokens that are not circulating are stored in addresses, like any other token. The difference is the addresses are convincingly out of circulation which requires a human review. It is subjective. Providing a list of those addresses and why they should be counted as uncirculating is part of the onboarding process for reporting sites such as coinmarketcap.
Price is also subjective. It's what someone is willing to pay for it. An ERC20 contract defines what it is. An app defines what you can use it for. An exchange discovers what someone is willing to pay for it.
There is a possibility of using an automated market maker such as Uniswap to discover a price. That is contingent on a liquidity pool existing and your assessment of how deep (and reliable) the price quote is. Other subtleties exist around the reliability of such quotes because such pools are vulnerable to price-manipulation attacks by wealthy attackers and coders using flash loans. Generally, one needs to use defensive patterns to avoid trouble. Bad assumptions about price quotes are responsible for a parade of DeFi hacks.
Hope it helps.