What I’m posting here are two completely different ways to create a solar system.
The first link is really about building a model of our solar system. I’ve used this with my class to build a scale model solar system. You can choose and object you’d like to use to represent the sun, measure it, put the measurement into this site, and it will tell you how big (and how far away) the other planets will be. You can then discuss as a class the feasibility of building the model. Students often want to start with something fairly large to be the sun (a beach ball, or basketball, for example). This works well in terms of making the planets big enough to be seen, but you’d have to walk a looong way to put them out at the right distance. If they choose too small of an object to be the sun, Mercury is too small to be seen. Planning a model helps students realize how empty space is, even within our solar system. Actually taking the objects you choose outside and building the model makes it much more memorable.
The second link isn’t about our solar system but about how all solar systems work. Students can choose the mass of their star(s), planet(s) and moon(s), choose their initial speed and trajectory and then let the program run, showing how this solar system would work. This activity reinforces the idea that all objects that have mass have gravity, and that the gravity of the orbiting object affects the movement of the object being orbited. Because the paths of each body are traced it also helps explain in a visual way the movement of planets and moons and comets. Playing around with this site is also a lot of fun. I would recommend starting out with the preset sun and planet model, then the preset sun, planet and moon before allowing students to explore. Later they can move on to examining potential multi-star solar systems and other fun stuff.