The aim of bowls is extremely simple: you roll a ball down a green and try to get closer to the jack (a smaller white ball) than your opponent. You might bowl two, three, or four bowls, depending on the player count, and, in most competitions, for each of your bowls that’s closer than your opponent’s you score one point.
So in the example below, the black bowls score two points.
There you are: you already know enough to start playing, and as long as there’s at least one other player on the rink who can run the game you’re ready to go.
Of course, as a long-established game, there are rules for every situation, such as how long a bowling green must be, the size of the mat that you bowl from, and what to do if someone hits the jack so hard it smashes into pieces. (The answer to the last is: the largest chunk is the bit that counts!) The latest version of the rules can be found on the World Bowls Website.
Below are a few more things that might make you feel more comfortable as a beginner. It’s also worth reading some basic terminology to explain what things like “an end” or “the head” is.