i agree with the guys for you to seek out help. a cub is not an easy plane to learn on without any help. you could easily break something just on the squirrelly take off run. get help!!! oh yeah... and getting a finger chopped up or worse, off, is definitely a good way to ensure you exit the hobby early.

as for the spilling out of fuel. this is likely because the level of your carb is significantly lower than the level of your tank. so what is happening is gravity is pulling out the fuel once you've primed it to start your engine. you've got to lower your tank so that the middle of the tank is about the level of the carb, otherwise you will always be flooding the carb. this is why having your engine side mounted is always safer than inverted.