Motorized Bike Urgent Help!?

I'm currently riding a grubee 48cc 2 stroke bike and its going well. after my break in period and a while after that i kept riding well. then out of no where when I'm about to ride it the next morning, i take it up my drive way and hold the cloth and ride it down. I'm expecting that when i let go of the cloth the motor will kick on after 10 mph down my drive way, but all the motor does it idle.. but no molter how hard I'm throttling, it just idles faster... like vroom vroom.. but with no chain pulling the wheel to make it move action.

i read somewhere on my maul that to not use ethanol fuel, but all these gas stations have some percentage of ethanol. now finally after starting like like 20 times the engine finally kicked in with the chain spying action and i take off. but when i stop i look at my exhaust as I'm getting off my motorized bike and i see a small amount of smoke coming out of the exhaust like oil burning in there. i usually measure in a tank 1 gallon and all 2.6 oz of oil lawnmower oil.

1) could my bike not start because of the ethol gas and how do i fix it

2) AM i putting a lot of oil cause it to smoke up in there.

3) When i get of my bike i find like black oil reside around the spark plug ring looking place.. what is that and how do i clean it up

please answer the question exactly..