In order to connect your wallet you have to click on the "Unlock Wallet" button on the top-right corner of the page. After that, look for the wallet you want to connect to Digicom Market and click "connect". Approve the connection and you're good to go.
When there is any official airdrop going on it will be announced along with the requirements.
Please remember anyone can airdrop tokens to users since every transaction is public on Polygonscan. Do your own due diligence when it comes to non-official airdrops.
$Digicom does have a maximum supply of 12,700,000 DCOM. The circulating supply is managed through built-in burning and regular burning events.