Unity’s Character Controller
While it is perfectly possible to use the Rigidbody component to control a character in Unity, there is also an explicit CharacterController component provided, which has a lot of built-in character features.
Things like slope limit and step offset are handy if you don’t want to try and figure all that out yourself. Because a lot of assumptions are made to make these things work however, you may find you have to forgo the standard character controller and build your own implementation of many features in order to get your character to function exactly the way you have in mind.
Another option is to visit the Unity Asset Store. Character control is so basic that a lot of developers have shared their own implementations, which can be purchased at very reasonable prices compared to the hours it would take you to build as much functionality yourself. If nothing else, this is a great source for inspiration, as you get to download the code and see how things are done, even if you don’t use everything just as someone else wrote it.