Start small (maybe even Premiere elements like HuntingBry suggested), but I think with the level of work you do, you would find yourself wanting to upgrade anyways, so it might be better to get what you want the first time around.

Become famaliar with the interface and menu locations. Get Premiere classroom in a book (published by Adobe). These books go over the more fundamental aspects of their programs (locations of menus, explanations of tools, shortcut keys, etc). Once you learn the interface, you will jump from all adobe apps pretty effortlessly because they all share VERY similar layouts, menus, and functions, and almost ALL keyboard shortcuts are the same. You will spend some time getting to know it, but it won't be long...if 10th graders can do it, so can you