Like any sport, paintball has a learning curve. As far as easy, most paintball fields have a lower age limit of 10 years old. Many fields may require you to view a safety video. So really, the basics are easy. learning to work as a team with a group might take some getting used to.
Scary? Once you figure out getting hit out isn't a big deal, you'll be able to think more about strategy and tactics. When you start contributing to winning or meeting objectives, then it becomes a challenge and it is always fun to win.
Different fields will have different areas and specialties. I suggest learning all you can. there are several variations and hopefully you have a good field near you. There are some bad ones, but having zero experience means you won't now the difference until you actually see it.
There are always idiots in large groups of people. Hopefully you can start out with a smaller beginner oriented group and avoid them. I've met a lot of good people in paintball over the years. I've also met a few jerks. Sooner or later the bad ones go away if they don't get outright banned.
I suggest renting initially, but if you find that you really like the sport, buy your own gear. Having your own stuff and maintaining it properly is usually better than the rentals.