Can I move elements of menu bar around, or add new elements?

Hello, apparently with the newest update to Firefox, they decided to change locations for elements like the sidebar and extension icons and the forward and back arrows. Is there any way to change these back to their previous locations (e.g., forward/back arrows on left side of search bar)? Also, I appear to be missing the icons for refreshing a page and opening a downloaded document. Where can I find these and how do I add them back to my header bars? I didn't find anything under the Settings menu. Any help appreciated, as these apparently tiny changes are driving me crazy. I especially miss the refresh and open download buttons. Thank you!