Revit model usually is not as complicated as an AutoCAD drawing. You can select objects easier before you modify it. However, in a complex model, you need a method to select multiple objects faster. You want to select them based on specific properties. For example, you want to select all walls with a specific type. Or you want to select all walls with a specific function.
We cover different methods in this article that you can use.
Modifying objects with AutoLISP: working with selection
We are going to modify objects with our AutoLISP program. But you need to learn how to select objects in AutoLISP first. Read how you can use SSGET!