Julie, I think it would be easier if you told us what you are trying to do or what does not work.
There is no harm in asking and there are no stupid questions, but sometimes to an experienced user some things are just so self-evident, that it is hard to think beyond that. 
Either cameras or tie points will be selected and highlighted in orange, either by a rectangle or a lasso.
I actually do think that in PS the lasso works similar, only that in RC you will not see a marked area like in PS but the objects will be selected immediately.
Just activate a 3D view with some tie points and some cameras and try them out - Iām sure you will figure it out!