The answer to 'how to fix faucet' is to first turn off the water supply to the faucet, then disassemble the faucet to access the internal components. You may need to replace worn washers, springs, or seals to stop a leaky faucet. For a dripping faucet, you may need to replace the cartridge or valve stem. Be sure to follow the manufacturer's instructions carefully when reassembling the faucet.
If you don't feel comfortable performing the repair yourself, it's best to call a licensed plumber to diagnose and fix the issue. Attempting a faucet repair without the proper tools and experience can lead to further damage.