How to simulate dynamic orbits with unity 2d gravity (realistic)

Question

I am making a simple game with unity’s 2d game engine and the game involves spacecraft/objects orbiting, accelerating and decelerating. I am wondering if this is possible with the default gravity or possibly by tweaking the default gravity of the rigidbodies/effectors.
I am a beginner learning c# and unity so I am looking for ideas, solutions and reccomendations on what to do.