You would do well to contact Hucky's and see what he can get you a complete kit for. Find Hucky's on the Web but call him to place orders. He will explain to you. Get as much stuff as he has in stock that you can afford right now. Get the Clymer's or the Haynes manual now. If you can't afford the complete new tool kit then tell us do you own metric tools?
If Hucky's only sells the BMW shop manual don't get that one. It is too much money for something not very useful for a beginner.
Look for "tool" on Ebay. You may find what you need. Hopefully, but I just did that and did not see a reasonable /5 tool kit in the lot.
The problem is that it is an on going evolving thing. The "tool kit" under the seat is only a start. You are going to need a lot of other tools as time goes by.
The German tools made for the bike are good tools. It would cost just as much to make the tool kit up at the Sears store.
There are several ordinary wrenches needed but there are also a couple of special wrenches you should have. These are hard to find if Hucky's doesn't have them. Recently we have sent riders there to get the specialty wrenches.
I think there is a picture of the tools in the manual. Please get a manual right away so we know what we are talking about.