A point is like a little dot on a piece of paper. It doesn't have any length, width, or height - it's just a location in space. You can think of it like a tiny mark you could make with a pen or pencil.
A line is like a straight path that goes on forever in both directions. It's made up of an infinite number of points all in a row. If you were to draw a line on a piece of paper, you would draw it with a straight edge like a ruler or a book.
An angle is the space between two lines that meet at a point. You can think of it like a corner, where two walls meet in a room. Angles can be big or small, depending on how wide the space is between the two lines.
So if you take two points and connect them with a line, you've created a straight path. If you take two lines and make them meet at a point, you've created an angle. And if you take three points and connect them with lines, you've created a triangle!