cut a model into "pieces"

Say you have a bodysuit that's all modeled as 1 piece
What I want to do is group this suit into different sections?
How would I do that?
Also, how can I delete a whole section? Like, I highlight a whole area in 1 go, not in the slow way of section every single face
Comments
For the first question, select what you want separate, edges, faces, and vertices > vertex tab > extract > drag translation handles to move it away. You'll know have a 2nd object in your scene tree.
For the second, select what you want gone and hit the delete key. Right click the viewport > lasso selection to get a chunk at a time.
thank you for the reply
the lasso helps so much
Especially when used after selecting transparent mode.