While not everyone likes to drink water, it is essential to our life, and not having fresh running water in our homes would be a major problem. Sometimes there could be strange smells emanating from the water in your faucet, and you might immediately wonder if it is safe to drink it. Say for example that you smell rotten eggs when your water starts running. That is likely from hydrogen sulfide. While it is harmful in large quantities, the smell will be obvious even from very small amounts of hydrogen sulfide, which is most likely the case for you.
Another common smell is that of chlorine. Chlorine is used to kill harmful bacteria in the water, so it is not a surprise that you occasionally smell it, but it is hardly ever in large enough quantities to be bad for your health.
For better water quality, you do have the option to install filters that will prevent these chemicals from making it into your glass.