Can I buy from Drops or mint my own NFT in the app?

Not in the app at the moment. The app covers the auction market and your wallet. Drops and minting are on market.creta.world, which needs a desktop browser with the Creta Wallet extension.

NFTs you mint or buy there show up in this app's wallet if you use the same seed phrase in both. You can sell them here once their collection is open for auction.