Help with Canvas Dimensions & Objects

Hey, I’m new to Bubble but am learning quickly.

I can’t seem to find the settings for the following:

A) How do I rename a page? I would like to rename from “index” to say, ‘Home’

B) How do determine the overall width of my page? And then make sure that all reusable elements are the same width? Because I’m facing this issue: In the builder, this object takes up most of the width: but when I preview it, It’s much smaller:

C) Why do images get cut off and distorted on preview? Builder mode: Preview mode:

D) Why do some items move to a different location in preview mode?
Builder mode: Preview mode:

I can’t seem to wrap my head around these minute styling details. I’ve tried so many things.
Maybe I’m just not familiar with the settings enough. If anyone can help, I would greatly appreciate it!