If you want to customise the toolbar you need to right click on the toolbar, not on the hamburger menu. Dragging a particular icon to the toolbar should position the icon where you dropped it.
It's really hard to help you because we don't understand what it is that your problem is. I have used Firefox for 20+ years & have never ever seen a 'Bookmarks tab'; if I have a web page open there are multiple ways to bookmark it, see above. Once bookmarked it can be edited, re-postioned, whatever.
The only thing that I can think of is that you have managed to close the Menu Bar, in which case right click at the very top of a web page & left click Menu Bar option.