You're not dumb, and you're not alone. LA's can be tricky to master, and there are many different reasons for tension problems and thread breakage. After a while you will get the hang of it, but don't hesitate to ask for help!!! You can get a lot of tips from the internet if you search - here's one for another machine, but most of it would apply to all makes -
http://www.longarmohio.com/tips.html There are also lots of yahoo groups devoted to longarming, all kinds, and the members are very helpful. I belong to the LongArm group, as well as several groups for the Innova.
Did you get a class from the shop where you bought your LA? They should be able to assist you with any questions specific to your machine. Good luck!