Spacing notes and Editing measures

I don't see a photo, but in general, the default spacing should already use fairly standard engraving rules for spacing. All notes aren't supposed to have the same space - it's important for people reading that half notes take more room than quarter notes etc.

The way to change the size of a measure depends on the context and whether you want it larger aor smaller, also how you want other measures affected. Instead of attaching a photo, we would really need you to attach your actual score and describe what you are trying to do in more detail