Yes, filters are quite handy in some campgrounds as many campgrounds are on wells, or have local water systems that have water with sulphur or other minerals that can be....how shall we say it....quite tasty! In the past, I've used bottled water for making coffee (the biggest problem with "tasty" water. For the past couple of years, I've been using the inexpensive Camco water filters that can be incorporated in your fresh water hose connection. They seem to do the job fairly well, and easy to replace as needed.
Some RVers prefer to use better water filter systems that are designed for homes that utilize two or three stages of filtration.
And, many don't ever use a filter. As you spend time camping/traveling, you'll find out what will work for you. If you are a coffee or tea drinker, I suggest at least picking up a Camco filter and have it available for the first time you hit a campground with "tasty" water. Walmart tends to have the best price on them, but they are easy to find online at Amazon or other retailers.