I am trying to calculate Realized Market Cap by looking at UTXOs in bitcoind the node I have in my computer. Has anyone tried before? Any guidance would help… Cheers.
You can’t really get the market cap from bitcoind because you don’t know the price of bitcoin on chain, for that you would either need to use some API from an exchange or Coingecko.
After you have the price you would need to scan the blockchain for all unspent UTXOs to sum them up to get the coins in circulation and multiply by the price of the coin. 
… the idea would be to scan for all unspent UTXO and assign them a date when they last move. Then I can multiply those values by an indicative price. Is it possible to do that?
UTXOs (Unspent TX Outputs) don’t move, they are spent and new ones are created as new unspent outputs. So you need to find those. Then you can multiply these values by price, but you would require a third party API to get the price.