If you install one version over the top of the other (i.e. don't uninstall first, which will wipe the config), it should import most settings. Toolbars get reset to defaults, but the old ones are still there. ( Your old toolbars are still there after you upgrade )
Going direct from 9 to 12 is a big jump though, so a lot of things may have changed. That is literally 10 years of difference.
If you need help with setting up particular things again, please start a new thread for each thing (unless they are related), and give more detail. (e.g. Which extension isn't doing what you want on double-click? What do you want it to do?)